Pub Date : 2025-01-01Epub Date: 2025-01-03DOI: 10.1038/s42005-024-01928-8
Adrian Montes Plaza, Janne Pakarinen, Philippos Papadakis, Rolf-Dietmar Herzberg, Rauno Julin, Tomás R Rodríguez, Andrew D Briscoe, Andrés Illana, Joonas Ojala, Panu Ruotsalainen, Eetu Uusikylä, Betool Alayed, Ahmed Alharbi, Odette Alonso-Sañudo, Kalle Auranen, Ville Bogdanoff, Jamie Chadderton, Arwin Esmaylzadeh, Christoph Fransen, Tuomas Grahn, Paul T Greenlees, Jan Jolie, Henna Joukainen, Henri Jutila, Casper-David Lakenbrink, Matti Leino, Jussi Louko, Minna Luoma, Adam McCarter, Bondili Sreenivasa Nara Singh, Panu Rahkila, Andrea Raggio, Jorge Romero, Jan Sarén, Maria-Magdalini Satrazani, Marek Stryjczyk, Conor M Sullivan, Álvaro Tolosa-Delgado, Juha Uusitalo, Franziskus von Spee, Jessica Warbinek, George L Zimba
Atomic nuclei serve as prime laboratories for investigations of complex quantum phenomena, where minor nucleon rearrangements cause significant structural changes. 190Pb is the heaviest known neutron-deficient Pb isotope that can exhibit three distinct shapes: prolate, oblate, and spherical, with nearly degenerate excitation energies. Here we report on the combined results from three state-of-the-art measurements to directly observe these deformations in 190Pb. Contrary to earlier interpretations, we associate the collective yrast band as predominantly oblate, while the non-yrast band with higher collectivity follows characteristics of more deformed, predominantly prolate bands. Direct measurement of the transition and γ-e- coincidence relations allowed us to locate and firmly assign the state in the level scheme and to discover a spherical state at 1281(1) keV with W.u. These assignments are based purely on observed transition probabilities and monopole strength values, and do not rely on model calculations for their interpretation.
{"title":"Direct measurement of three different deformations near the ground state in an atomic nucleus.","authors":"Adrian Montes Plaza, Janne Pakarinen, Philippos Papadakis, Rolf-Dietmar Herzberg, Rauno Julin, Tomás R Rodríguez, Andrew D Briscoe, Andrés Illana, Joonas Ojala, Panu Ruotsalainen, Eetu Uusikylä, Betool Alayed, Ahmed Alharbi, Odette Alonso-Sañudo, Kalle Auranen, Ville Bogdanoff, Jamie Chadderton, Arwin Esmaylzadeh, Christoph Fransen, Tuomas Grahn, Paul T Greenlees, Jan Jolie, Henna Joukainen, Henri Jutila, Casper-David Lakenbrink, Matti Leino, Jussi Louko, Minna Luoma, Adam McCarter, Bondili Sreenivasa Nara Singh, Panu Rahkila, Andrea Raggio, Jorge Romero, Jan Sarén, Maria-Magdalini Satrazani, Marek Stryjczyk, Conor M Sullivan, Álvaro Tolosa-Delgado, Juha Uusitalo, Franziskus von Spee, Jessica Warbinek, George L Zimba","doi":"10.1038/s42005-024-01928-8","DOIUrl":"10.1038/s42005-024-01928-8","url":null,"abstract":"<p><p>Atomic nuclei serve as prime laboratories for investigations of complex quantum phenomena, where minor nucleon rearrangements cause significant structural changes. <sup>190</sup>Pb is the heaviest known neutron-deficient Pb isotope that can exhibit three distinct shapes: prolate, oblate, and spherical, with nearly degenerate excitation energies. Here we report on the combined results from three state-of-the-art measurements to directly observe these deformations in <sup>190</sup>Pb. Contrary to earlier interpretations, we associate the collective yrast band as predominantly oblate, while the non-yrast band with higher collectivity follows characteristics of more deformed, predominantly prolate bands. Direct measurement of the <math><mi>E</mi> <mn>0</mn> <mrow><mo>(</mo> <mrow> <msubsup><mrow><mn>0</mn></mrow> <mrow><mn>2</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> <mo>→</mo> <msubsup><mrow><mn>0</mn></mrow> <mrow><mn>1</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </mrow> <mo>)</mo></mrow> </math> transition and <i>γ</i>-<i>e</i> <sup>-</sup> coincidence relations allowed us to locate and firmly assign the <math> <msubsup><mrow><mn>0</mn></mrow> <mrow><mn>2</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </math> state in the level scheme and to discover a spherical <math> <msubsup><mrow><mn>2</mn></mrow> <mrow><mn>3</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </math> state at 1281(1) keV with <math><mi>B</mi> <mrow><mo>(</mo> <mrow><mi>E</mi> <mn>2</mn> <mo>;</mo> <msubsup><mrow><mn>2</mn></mrow> <mrow><mn>3</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> <mo>→</mo> <msubsup><mrow><mn>0</mn></mrow> <mrow><mn>1</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </mrow> <mo>)</mo></mrow> <mo>=</mo> <mn>1.2</mn> <mrow><mo>(</mo> <mrow><mn>3</mn></mrow> <mo>)</mo></mrow> </math> W.u. These assignments are based purely on observed transition probabilities and monopole strength values, and do not rely on model calculations for their interpretation.</p>","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":"8 1","pages":"8"},"PeriodicalIF":5.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11721533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142969914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-30DOI: 10.1038/s42005-024-01927-9
Ke Cheng, Meiying Hou, Wei Sun, Zhihong Qiao, Xiang Li, Chufan Lai, Jinchao Yuan, Tuo Li, Fangfu Ye, Ke Chen, Mingcheng Yang
Our experiments aboard the Chinese Space Station reveal a gravity-driven transition in intruder dynamics within vibrated granular media. While vibrations typically enable an intruder to ascend in a granular bed, low-gravity conditions induce it to descend under similar vibrations. Using a Hall-sensor array tracking method, we monitor the intruder’s movement throughout each vibration cycle and identified two competing mechanisms: inertia and gravity-dependent penetration. As gravity decreases, we observe a significant reduction in the scaled damping coefficient and hydrostatic pressure coefficient indicating that bed particles disperse more readily upon intruder impact, facilitating deeper penetration. Our findings highlight a critical transition from downward to upward motion of the intruder as vibration acceleration exceeds a threshold, which increases as gravity decreases. These insights into intruder dynamics in low-gravity environments have significant implications for asteroid exploration and lunar base construction, enhancing our understanding of the Brazil nut effect and the formation of planetesimal. Granular segregation may play a role in shaping the surface features of small celestial bodies such as asteroids that can be explained with the Brazil-nut effect. The authors study intruder dynamics in granular media on board the Chinese Space Station, finding that contrary to what occurs on Earth intruders tend to descend in microgravity conditions under specific vibration parameters
{"title":"Unraveling the role of gravity in shaping intruder dynamics within vibrated granular media","authors":"Ke Cheng, Meiying Hou, Wei Sun, Zhihong Qiao, Xiang Li, Chufan Lai, Jinchao Yuan, Tuo Li, Fangfu Ye, Ke Chen, Mingcheng Yang","doi":"10.1038/s42005-024-01927-9","DOIUrl":"10.1038/s42005-024-01927-9","url":null,"abstract":"Our experiments aboard the Chinese Space Station reveal a gravity-driven transition in intruder dynamics within vibrated granular media. While vibrations typically enable an intruder to ascend in a granular bed, low-gravity conditions induce it to descend under similar vibrations. Using a Hall-sensor array tracking method, we monitor the intruder’s movement throughout each vibration cycle and identified two competing mechanisms: inertia and gravity-dependent penetration. As gravity decreases, we observe a significant reduction in the scaled damping coefficient and hydrostatic pressure coefficient indicating that bed particles disperse more readily upon intruder impact, facilitating deeper penetration. Our findings highlight a critical transition from downward to upward motion of the intruder as vibration acceleration exceeds a threshold, which increases as gravity decreases. These insights into intruder dynamics in low-gravity environments have significant implications for asteroid exploration and lunar base construction, enhancing our understanding of the Brazil nut effect and the formation of planetesimal. Granular segregation may play a role in shaping the surface features of small celestial bodies such as asteroids that can be explained with the Brazil-nut effect. The authors study intruder dynamics in granular media on board the Chinese Space Station, finding that contrary to what occurs on Earth intruders tend to descend in microgravity conditions under specific vibration parameters","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-10"},"PeriodicalIF":5.4,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01927-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The emergence of nontrivial quantum states from competing interactions is a central issue in quantum magnetism. In particular, for the realization of the quantum spin-liquid state, extensive studies have been conducted on frustrated systems, such as kagome antiferromagnets and Kitaev magnets. Novel quantum states in magnetic fields have remained elusive despite the prediction of rich physics. This can be attributed to material scarcity and the difficulty of precise measurements under ultra-high magnetic fields. Here, in this study, we develop the Kapellasite-type compound InCu3(OH)6Cl3, whose exchange interactions are in appropriate energy scale to comprehensively elucidate the magnetic properties of the frustrated S = 1/2 kagome antiferromagnet. The one-third magnetization plateau was clearly observed. Moreover, the large temperature-linear term in the heat capacity was observed in the magnetic fields, indicating the excitation of gapless quasiparticles in the vicinity of the plateau. These results shed light on the critical behaviors between quantum spin-liquid and -solid in kagome antiferromagnets under high magnetic fields. A range of non-trivial quantum phenomena can emerge from frustrated magnetic systems and a prime example is a quantum spin liquid. Here, the authors conduct specific heat and magnetization measurements on the Kapellasite-type compound InCu3(OH)6Cl3 in order to characterize and define the range of the magnetization plateau in this material.
{"title":"One-third magnetization plateau in Quantum Kagome antiferromagnet","authors":"Moyu Kato, Yasuo Narumi, Katsuhiro Morita, Yoshitaka Matsushita, Shuhei Fukuoka, Satoshi Yamashita, Yasuhiro Nakazawa, Migaku Oda, Hiroaki Hayashi, Kazunari Yamaura, Masayuki Hagiwara, Hiroyuki K. Yoshida","doi":"10.1038/s42005-024-01922-0","DOIUrl":"10.1038/s42005-024-01922-0","url":null,"abstract":"The emergence of nontrivial quantum states from competing interactions is a central issue in quantum magnetism. In particular, for the realization of the quantum spin-liquid state, extensive studies have been conducted on frustrated systems, such as kagome antiferromagnets and Kitaev magnets. Novel quantum states in magnetic fields have remained elusive despite the prediction of rich physics. This can be attributed to material scarcity and the difficulty of precise measurements under ultra-high magnetic fields. Here, in this study, we develop the Kapellasite-type compound InCu3(OH)6Cl3, whose exchange interactions are in appropriate energy scale to comprehensively elucidate the magnetic properties of the frustrated S = 1/2 kagome antiferromagnet. The one-third magnetization plateau was clearly observed. Moreover, the large temperature-linear term in the heat capacity was observed in the magnetic fields, indicating the excitation of gapless quasiparticles in the vicinity of the plateau. These results shed light on the critical behaviors between quantum spin-liquid and -solid in kagome antiferromagnets under high magnetic fields. A range of non-trivial quantum phenomena can emerge from frustrated magnetic systems and a prime example is a quantum spin liquid. Here, the authors conduct specific heat and magnetization measurements on the Kapellasite-type compound InCu3(OH)6Cl3 in order to characterize and define the range of the magnetization plateau in this material.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01922-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-27DOI: 10.1038/s42005-024-01920-2
Yue Xiao, Yongxu Peng, Linfeng Chen, Chunhui Li, Zongao Song, Xin Wang, Tao Wang, Yurun Xie, Bin Zhao, Tiangang Yang
Laser cooling typically requires one or more repump lasers to clear dark states, which complicates experimental setups, especially for systems with multiple repumping frequencies. Here, we demonstrate cooling of Be+ ions using a single laser beam, enabled by micromotion-induced one-dimensional heating. By manipulating the displacement of Be+ ions from the trap’s nodal line, we precisely control the ion micromotion velocity, eliminating the necessity of a 1.25 GHz offset repump laser while keeping ions cold in the direction perpendicular to the micromotion. We use two equivalent schemes, cooling laser detuning and ion trajectory imaging to measure the speed of the Be+ ions, with results accurately reproduced by molecular dynamics simulations based on a machine learned time-dependent electric field inside the trap. This work provides a robust method to control micromotion velocity of ions and demonstrates the potential of micromotion-assisted laser cooling to simplify setups for systems requiring multiple repumping frequencies. Reducing the number of lasers in laser cooling experiments is beneficial for simplifying systems requiring multiple repumping frequencies. This work demonstrates micromotion-assisted cooling of Be+ ions with a single laser, eliminating the need for a 1.25 GHz offset repump laser, with results rigorously validated through molecular dynamics simulations.
{"title":"Two-dimensional cooling without repump laser beams through ion motional heating","authors":"Yue Xiao, Yongxu Peng, Linfeng Chen, Chunhui Li, Zongao Song, Xin Wang, Tao Wang, Yurun Xie, Bin Zhao, Tiangang Yang","doi":"10.1038/s42005-024-01920-2","DOIUrl":"10.1038/s42005-024-01920-2","url":null,"abstract":"Laser cooling typically requires one or more repump lasers to clear dark states, which complicates experimental setups, especially for systems with multiple repumping frequencies. Here, we demonstrate cooling of Be+ ions using a single laser beam, enabled by micromotion-induced one-dimensional heating. By manipulating the displacement of Be+ ions from the trap’s nodal line, we precisely control the ion micromotion velocity, eliminating the necessity of a 1.25 GHz offset repump laser while keeping ions cold in the direction perpendicular to the micromotion. We use two equivalent schemes, cooling laser detuning and ion trajectory imaging to measure the speed of the Be+ ions, with results accurately reproduced by molecular dynamics simulations based on a machine learned time-dependent electric field inside the trap. This work provides a robust method to control micromotion velocity of ions and demonstrates the potential of micromotion-assisted laser cooling to simplify setups for systems requiring multiple repumping frequencies. Reducing the number of lasers in laser cooling experiments is beneficial for simplifying systems requiring multiple repumping frequencies. This work demonstrates micromotion-assisted cooling of Be+ ions with a single laser, eliminating the need for a 1.25 GHz offset repump laser, with results rigorously validated through molecular dynamics simulations.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01920-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-26DOI: 10.1038/s42005-024-01896-z
The DarkSide-20k Collaboration
The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV c−2. This was demonstrated by the DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV c−2 particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP–nucleon interaction cross-sections below 1 × 10−42 cm2 is achievable for WIMP masses above 800 MeV c−2. With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV c−2. The DarkSide-20k collaboration reports the sensitivity of its detector, currently under construction, to models predicting light dark matter particles. This includes Weakly Interacting Massive Particles and particles interacting with bound electrons of argon atoms.
{"title":"DarkSide-20k sensitivity to light dark matter particles","authors":"The DarkSide-20k Collaboration","doi":"10.1038/s42005-024-01896-z","DOIUrl":"10.1038/s42005-024-01896-z","url":null,"abstract":"The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV c−2. This was demonstrated by the DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV c−2 particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP–nucleon interaction cross-sections below 1 × 10−42 cm2 is achievable for WIMP masses above 800 MeV c−2. With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV c−2. The DarkSide-20k collaboration reports the sensitivity of its detector, currently under construction, to models predicting light dark matter particles. This includes Weakly Interacting Massive Particles and particles interacting with bound electrons of argon atoms.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-9"},"PeriodicalIF":5.4,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01896-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-24DOI: 10.1038/s42005-024-01909-x
Riccardo Gallotti, Davide Maniscalco, Marc Barthelemy, Manlio De Domenico
The description of human mobility is at the core of many fundamental applications ranging from urbanism and transportation to epidemics containment. Data about human movements, once scarce, is now widely available thanks to new sources such as phone call detail records, GPS devices, or Smartphone apps. Nevertheless, it is still common to rely on a single dataset by implicitly assuming that the statistical properties observed are robust regardless of data gathering and processing techniques. Here, we test this assumption on a broad scale by comparing human mobility datasets obtained from 7 different data-sources, tracing 500+ millions individuals in 145 countries. We report wide quantifiable differences in the resulting mobility networks and in the displacement distribution. These variations impact processes taking place on these networks like epidemic spreading. Our results point to the need for disclosing the data processing and, overall, to follow good practices to ensure robust and reproducible results. Human mobility data is crucial for many applications, but researchers often rely on single datasets assuming universal validity. Comparing 7 diverse sources across 145 countries, we find significant differences in mobility patterns and networks, impacting applications like epidemic modeling and emphasizing the need for transparent data processing.
{"title":"Distorted insights from human mobility data","authors":"Riccardo Gallotti, Davide Maniscalco, Marc Barthelemy, Manlio De Domenico","doi":"10.1038/s42005-024-01909-x","DOIUrl":"10.1038/s42005-024-01909-x","url":null,"abstract":"The description of human mobility is at the core of many fundamental applications ranging from urbanism and transportation to epidemics containment. Data about human movements, once scarce, is now widely available thanks to new sources such as phone call detail records, GPS devices, or Smartphone apps. Nevertheless, it is still common to rely on a single dataset by implicitly assuming that the statistical properties observed are robust regardless of data gathering and processing techniques. Here, we test this assumption on a broad scale by comparing human mobility datasets obtained from 7 different data-sources, tracing 500+ millions individuals in 145 countries. We report wide quantifiable differences in the resulting mobility networks and in the displacement distribution. These variations impact processes taking place on these networks like epidemic spreading. Our results point to the need for disclosing the data processing and, overall, to follow good practices to ensure robust and reproducible results. Human mobility data is crucial for many applications, but researchers often rely on single datasets assuming universal validity. Comparing 7 diverse sources across 145 countries, we find significant differences in mobility patterns and networks, impacting applications like epidemic modeling and emphasizing the need for transparent data processing.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-10"},"PeriodicalIF":5.4,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01909-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-23DOI: 10.1038/s42005-024-01915-z
Junsheng Hou, Dongyu Li, Lei Huang, Li Ma, Xiong Zhao, Jinjia Wei, Nanjing Hao
Contactless acoustics provide a unique, flexible active means for phase-change heat transfer enhancement. However, the ultrasonic transducers used for conventional acoustic enhancement are bulky and unfavorable for integration, and the heat accumulation under high power is not conducive to long-term operation, with limited enhancement in the critical heat flux (CHF). Herein, an acoustic-enabled low-power compact heat exchanger (ALCHE) is proposed with low energy consumption and long operation duration. Based on image processing and bubble tracking algorithm, it is found that the acoustic field accelerates bubble detachment and migration for achieving superior heat flux and larger heat transfer coefficient (HTC). 1.5 kHz acoustic field performs better heat transfer performance due to its strong acoustic radiation force magnitude and excellent acoustic pressure field direction. The stronger acoustic radiation force from higher acoustic power promotes the heat transfer performance among different acoustic powers. Long-time stable operation of acoustic field enhanced heat transfer under high heat flux is achieved with low acoustic power. Our designed heat exchanger not only overcomes the limitation of traditional bulky transducers, but also provides insights into the acoustic-enabled flow boiling heat transfer process. Improving the cooling performance of high-power electronics in confined spaces remains a challenge. Herein, the authors propose an acoustic-enabled low-power compact heat exchanger that utilizes contactless acoustics as a flexible active means for enhancing phase change cooling.
{"title":"Electronic cooling via acoustic-enabled low-power compact heat exchanger","authors":"Junsheng Hou, Dongyu Li, Lei Huang, Li Ma, Xiong Zhao, Jinjia Wei, Nanjing Hao","doi":"10.1038/s42005-024-01915-z","DOIUrl":"10.1038/s42005-024-01915-z","url":null,"abstract":"Contactless acoustics provide a unique, flexible active means for phase-change heat transfer enhancement. However, the ultrasonic transducers used for conventional acoustic enhancement are bulky and unfavorable for integration, and the heat accumulation under high power is not conducive to long-term operation, with limited enhancement in the critical heat flux (CHF). Herein, an acoustic-enabled low-power compact heat exchanger (ALCHE) is proposed with low energy consumption and long operation duration. Based on image processing and bubble tracking algorithm, it is found that the acoustic field accelerates bubble detachment and migration for achieving superior heat flux and larger heat transfer coefficient (HTC). 1.5 kHz acoustic field performs better heat transfer performance due to its strong acoustic radiation force magnitude and excellent acoustic pressure field direction. The stronger acoustic radiation force from higher acoustic power promotes the heat transfer performance among different acoustic powers. Long-time stable operation of acoustic field enhanced heat transfer under high heat flux is achieved with low acoustic power. Our designed heat exchanger not only overcomes the limitation of traditional bulky transducers, but also provides insights into the acoustic-enabled flow boiling heat transfer process. Improving the cooling performance of high-power electronics in confined spaces remains a challenge. Herein, the authors propose an acoustic-enabled low-power compact heat exchanger that utilizes contactless acoustics as a flexible active means for enhancing phase change cooling.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-9"},"PeriodicalIF":5.4,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01915-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142870536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anomalous Floquet topological phases are unique to periodically driven systems, lacking a static analog. Inspired by Floquet Engineering with classical electromagnetic radiation, Quantum Floquet Engineering has emerged as a promising tool to tailor the properties of quantum materials using quantum light. While the latter recovers the physics of Floquet materials in its semi-classical limit, the mapping between these two scenarios remains mysterious in many aspects. In this work, we discuss the emergence of quantum anomalous topological phases in cavity-QED materials, linking the topological phase transitions in the electron-photon spectrum with those in the 0- and π-gaps of Floquet quasienergies. Our results establish the microscopic origin of an emergent discrete time-translation symmetry in the matter sector, and link isolated c-QED materials with periodically driven ones. Finally, we discuss the bulk-edge correspondence in terms of hybrid light-matter topological invariants. Non-equilibrium systems subject to periodic driving fields, known as Floquet materials, can host unique topological phases without static counterpart. This work targets the link between Floquet physics and cavity-QED systems, and unveils the emergence of quantum anomalous phases in the latter, pointing to the important entangled light-matter dynamics.
{"title":"Quantum origin of anomalous Floquet phases in cavity-QED materials","authors":"Beatriz Pérez-González, Gloria Platero, Álvaro Gómez-León","doi":"10.1038/s42005-024-01908-y","DOIUrl":"10.1038/s42005-024-01908-y","url":null,"abstract":"Anomalous Floquet topological phases are unique to periodically driven systems, lacking a static analog. Inspired by Floquet Engineering with classical electromagnetic radiation, Quantum Floquet Engineering has emerged as a promising tool to tailor the properties of quantum materials using quantum light. While the latter recovers the physics of Floquet materials in its semi-classical limit, the mapping between these two scenarios remains mysterious in many aspects. In this work, we discuss the emergence of quantum anomalous topological phases in cavity-QED materials, linking the topological phase transitions in the electron-photon spectrum with those in the 0- and π-gaps of Floquet quasienergies. Our results establish the microscopic origin of an emergent discrete time-translation symmetry in the matter sector, and link isolated c-QED materials with periodically driven ones. Finally, we discuss the bulk-edge correspondence in terms of hybrid light-matter topological invariants. Non-equilibrium systems subject to periodic driving fields, known as Floquet materials, can host unique topological phases without static counterpart. This work targets the link between Floquet physics and cavity-QED systems, and unveils the emergence of quantum anomalous phases in the latter, pointing to the important entangled light-matter dynamics.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-9"},"PeriodicalIF":5.4,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01908-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-20DOI: 10.1038/s42005-024-01902-4
Seokyeong Lee, Dongsung T. Park, Uhjin Kim, Hwanchul Jung, Yunchul Chung, Hyoungsoon Choi, Hyung Kook Choi
Transverse magnetic focusing (TMF) is a staple technique in mesoscopic physics, used to study quasiparticles in a manner akin to mass spectrometry. However, the quantum nature of TMF has been difficult to appreciate due to several challenges in addressing the wavelike properties of the quasiparticles. Here, we report a numerical solution and experimental demonstration of the TMF wavefunction for the multichannel case, implemented using quantum point contacts in a two-dimensional electron gas. The wavefunctions could be understood as transverse modes of the emitter tracing a classical trajectory, and the geometric origins of multichannel effects were easily intuited from this simple picture. We believe our results may correspond to a near-field regime of TMF, in contrast to a far-field regime where the well-established semiclassical results are valid. Based on disorder analysis, we expect these results will apply to a wide range of realistic devices, suggesting that spatially coherent features even at the wavelength scale can be appreciated from TMF. Transverse magnetic focusing (TMF) has been widely used in mesoscopic physics, yet its quantum mechanical properties remain difficult to fully appreciate. Here, the authors present a numerical solution of TMF, analysed with channel-resolution and compared against experimental data, to expose the multichannel signatures of the TMF wavefunction.
{"title":"Channel-resolved wavefunctions of transverse magnetic focusing","authors":"Seokyeong Lee, Dongsung T. Park, Uhjin Kim, Hwanchul Jung, Yunchul Chung, Hyoungsoon Choi, Hyung Kook Choi","doi":"10.1038/s42005-024-01902-4","DOIUrl":"10.1038/s42005-024-01902-4","url":null,"abstract":"Transverse magnetic focusing (TMF) is a staple technique in mesoscopic physics, used to study quasiparticles in a manner akin to mass spectrometry. However, the quantum nature of TMF has been difficult to appreciate due to several challenges in addressing the wavelike properties of the quasiparticles. Here, we report a numerical solution and experimental demonstration of the TMF wavefunction for the multichannel case, implemented using quantum point contacts in a two-dimensional electron gas. The wavefunctions could be understood as transverse modes of the emitter tracing a classical trajectory, and the geometric origins of multichannel effects were easily intuited from this simple picture. We believe our results may correspond to a near-field regime of TMF, in contrast to a far-field regime where the well-established semiclassical results are valid. Based on disorder analysis, we expect these results will apply to a wide range of realistic devices, suggesting that spatially coherent features even at the wavelength scale can be appreciated from TMF. Transverse magnetic focusing (TMF) has been widely used in mesoscopic physics, yet its quantum mechanical properties remain difficult to fully appreciate. Here, the authors present a numerical solution of TMF, analysed with channel-resolution and compared against experimental data, to expose the multichannel signatures of the TMF wavefunction.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01902-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-20DOI: 10.1038/s42005-024-01910-4
Litong Xu, Tingting Xi
Ultraviolet pulses could open up new opportunities for the study of strong-field physics and ultrafast science. However, the existing methods for generating ultraviolet pulses face difficulties in fulfilling the twofold requirements of high energy and wavelength tunability simultaneously. Here, we theoretically demonstrate the generation of high-energy and wavelength tunable ultraviolet pulses in preformed gas-plasma channels via the leaky wave emission. The output ultraviolet pulse has a tunable wavelength ranging from 91 nm to 430 nm, and an energy level up to sub-mJ. Such a high-energy tunable ultraviolet light source may provide promising opportunities for characterization of ultrafast phenomena, and also an important driving source for the generation of high-energy attosecond pulses. High-energy ultraviolet pulses serve as unique light sources for strong-field physics and ultrafast science. The authors theoretically demonstrate the generation of ultraviolet pulses with sub-mJ level energy via optical leaky wave in filamentation, where preformed gasplasma channels are used to provide adjustable dispersion conditions that enable a widely tunable wavelength range of the ultraviolet pulses.
{"title":"High-energy tunable ultraviolet pulses generated by optical leaky wave in filamentation","authors":"Litong Xu, Tingting Xi","doi":"10.1038/s42005-024-01910-4","DOIUrl":"10.1038/s42005-024-01910-4","url":null,"abstract":"Ultraviolet pulses could open up new opportunities for the study of strong-field physics and ultrafast science. However, the existing methods for generating ultraviolet pulses face difficulties in fulfilling the twofold requirements of high energy and wavelength tunability simultaneously. Here, we theoretically demonstrate the generation of high-energy and wavelength tunable ultraviolet pulses in preformed gas-plasma channels via the leaky wave emission. The output ultraviolet pulse has a tunable wavelength ranging from 91 nm to 430 nm, and an energy level up to sub-mJ. Such a high-energy tunable ultraviolet light source may provide promising opportunities for characterization of ultrafast phenomena, and also an important driving source for the generation of high-energy attosecond pulses. High-energy ultraviolet pulses serve as unique light sources for strong-field physics and ultrafast science. The authors theoretically demonstrate the generation of ultraviolet pulses with sub-mJ level energy via optical leaky wave in filamentation, where preformed gasplasma channels are used to provide adjustable dispersion conditions that enable a widely tunable wavelength range of the ultraviolet pulses.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01910-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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