Ian Sequeira, Andrew Z. Barabas, Aaron H Barajas-Aguilar, Michaela G Bacani, Naoto Nakatsuji, Mikito Koshino, Takashi Taniguichi, Kenji Watanabe, Javier D. Sanchez-Yamagishi
Van der Waals (vdW) moires offer tunable superlattices that can strongly manipulate electronic properties. We demonstrate the in-situ manipulation of moire superlattices via heterostrain control in a vdW device. By straining a graphene layer relative to its hexagonal boron nitride substrate, we modify the shape and size of the moire. Our sliding-based technique achieves uniaxial heterostrain values exceeding 1%, resulting in distorted moires that are larger than those achievable without strain. The stretched moire is evident in transport measurements, resulting in shifted superlattice resistance peaks and Landau fans consistent with an enlarged superlattice unit cell. Electronic structure calculations reveal how heterostrain shrinks and distorts the moire Brillouin zone, resulting in a reduced electronic bandwidth as well as the appearance of highly anisotropic and quasi-1-dimensional Fermi surfaces. Our heterostrain control approach opens a wide parameter space of moire lattices to explore beyond what is possible by twist angle control alone.
{"title":"Manipulating moires by controlling heterostrain in van der Waals devices","authors":"Ian Sequeira, Andrew Z. Barabas, Aaron H Barajas-Aguilar, Michaela G Bacani, Naoto Nakatsuji, Mikito Koshino, Takashi Taniguichi, Kenji Watanabe, Javier D. Sanchez-Yamagishi","doi":"arxiv-2409.07427","DOIUrl":"https://doi.org/arxiv-2409.07427","url":null,"abstract":"Van der Waals (vdW) moires offer tunable superlattices that can strongly\u0000manipulate electronic properties. We demonstrate the in-situ manipulation of\u0000moire superlattices via heterostrain control in a vdW device. By straining a\u0000graphene layer relative to its hexagonal boron nitride substrate, we modify the\u0000shape and size of the moire. Our sliding-based technique achieves uniaxial\u0000heterostrain values exceeding 1%, resulting in distorted moires that are larger\u0000than those achievable without strain. The stretched moire is evident in\u0000transport measurements, resulting in shifted superlattice resistance peaks and\u0000Landau fans consistent with an enlarged superlattice unit cell. Electronic\u0000structure calculations reveal how heterostrain shrinks and distorts the moire\u0000Brillouin zone, resulting in a reduced electronic bandwidth as well as the\u0000appearance of highly anisotropic and quasi-1-dimensional Fermi surfaces. Our\u0000heterostrain control approach opens a wide parameter space of moire lattices to\u0000explore beyond what is possible by twist angle control alone.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"71 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose and demonstrate a static quantum dot on a potential hilltop to generate and analyze ballistic hot electrons along a quantum Hall edge channel well above the chemical potential. High energy resolution associated with discrete energy levels is attractive for studying hot-electron dynamics. Particularly, the energy distribution function of hot electrons weakly coupled to cold electrons is investigated to reveal spectral diffusion with energy relaxation. The analysis allows us to estimate the maximum energy exchange per scattering, which is an important parameter to describe interacting electrons in the edge channel.
{"title":"Static quantum dot on a potential hilltop for generating and analyzing hot electrons in the quantum Hall regime","authors":"Ryo Oishi, Yuto Hongu, Tokuro Hata, Chaojing Lin, Takafumi Akiho, Koji Muraki, Toshimasa Fujisawa","doi":"arxiv-2409.07061","DOIUrl":"https://doi.org/arxiv-2409.07061","url":null,"abstract":"We propose and demonstrate a static quantum dot on a potential hilltop to\u0000generate and analyze ballistic hot electrons along a quantum Hall edge channel\u0000well above the chemical potential. High energy resolution associated with\u0000discrete energy levels is attractive for studying hot-electron dynamics.\u0000Particularly, the energy distribution function of hot electrons weakly coupled\u0000to cold electrons is investigated to reveal spectral diffusion with energy\u0000relaxation. The analysis allows us to estimate the maximum energy exchange per\u0000scattering, which is an important parameter to describe interacting electrons\u0000in the edge channel.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tomonari Meguro, Akihiro Ozawa, Koji Kobayashi, Yasufumi Araki, Kentaro Nomura
The spin-orbit torque (SOT) in a compensated ferrimagnetic Weyl semimetal, ${rm Ti}_{2}{rm MnAl}$, is studied by the linear response theory. We elucidate that the SOT driven by all the occupied electronic states is present in magnetic Weyl semimetal, unlike in conventional metallic magnets. Around the energy of the Weyl points, we find that such an SOT is dominant and almost independent of the disorder. The emergence of the SOT in ${rm Ti}_{2}{rm MnAl}$ can be understood from the structure of the mixed Berry curvature around the Weyl points, which is similar to that of the ordinary Berry curvature.
通过线性响应理论研究了补偿铁磁性韦尔半金属${rm Ti}_{2}{rm MnAl}$中的自旋轨道力矩（SOT）。我们发现，与传统金属磁体不同，磁性韦尔半金属中存在由所有占据的电子态驱动的 SOT。我们发现，在韦尔点能量附近，这种 SOT 占主导地位，几乎与无序无关。在 ${rm Ti}_{2}{rmMnAl}$中出现的 SOT 可以从韦尔点周围的混合贝里曲率的结构来理解，它与普通贝里曲率的结构相似。
{"title":"Topological Spin-Orbit Torque in Ferrimagnetic Weyl Semimetal","authors":"Tomonari Meguro, Akihiro Ozawa, Koji Kobayashi, Yasufumi Araki, Kentaro Nomura","doi":"arxiv-2409.07106","DOIUrl":"https://doi.org/arxiv-2409.07106","url":null,"abstract":"The spin-orbit torque (SOT) in a compensated ferrimagnetic Weyl semimetal,\u0000${rm Ti}_{2}{rm MnAl}$, is studied by the linear response theory. We\u0000elucidate that the SOT driven by all the occupied electronic states is present\u0000in magnetic Weyl semimetal, unlike in conventional metallic magnets. Around the\u0000energy of the Weyl points, we find that such an SOT is dominant and almost\u0000independent of the disorder. The emergence of the SOT in ${rm Ti}_{2}{rm\u0000MnAl}$ can be understood from the structure of the mixed Berry curvature around\u0000the Weyl points, which is similar to that of the ordinary Berry curvature.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ni-Mo superalloys have emerged as materials of choice for a diverse array of applications owing to their superior mechanical properties, exceptional corrosion and oxidation resistance, electrocatalytic behavior, and surface stability. Understanding and optimizing the surface composition of Ni-Mo alloys is critical for enhancing their performance in practical applications. Traditional experimental surface analysis techniques, while informative, are often prohibitive in terms of cost and time. Likewise, theoretical approaches such as first-principle calculations demand substantial computational resources and it is difficult to simulate large structures. This study introduces an alternative approach utilizing hybrid Monte-Carlo / Molecular Dynamics (MC/MD) simulations to investigate the surface composition of Ni-Mo alloys. We report the development of an optimized Embedded-Atom Method (EAM) potential specifically for Ni-Mo alloys, carefully parameterized using empirical lattice constants and formation energies of elemental and face-centered cubic (FCC) Ni-Mo solid solution alloys. The reliability of the EAM potential is corroborated via the evaluation of equations of state, with a particular focus on reproducing structural properties. Utilizing this validated potential, MC/MD simulations were performed to understand the depth-wise variations in the compositions of Ni-Mo alloy nanoparticles and extended surfaces. These simulations reveal a preferential segregation of nickel on surface, and molybdenum in sub-surface layer. Due to this preferential segregation, it is imperative to consider surface segregation while tailoring the surface properties for targeted applications.
{"title":"Development of an embedded-atom method potential of Ni-Mo alloys for electrocatalysis / surface compositional studies","authors":"Ambesh Gupta, Chinmay Dahale, Soumyadipta Maiti, Sriram Goverapet Srinivasan, Beena Rai","doi":"arxiv-2409.07320","DOIUrl":"https://doi.org/arxiv-2409.07320","url":null,"abstract":"Ni-Mo superalloys have emerged as materials of choice for a diverse array of\u0000applications owing to their superior mechanical properties, exceptional\u0000corrosion and oxidation resistance, electrocatalytic behavior, and surface\u0000stability. Understanding and optimizing the surface composition of Ni-Mo alloys\u0000is critical for enhancing their performance in practical applications.\u0000Traditional experimental surface analysis techniques, while informative, are\u0000often prohibitive in terms of cost and time. Likewise, theoretical approaches\u0000such as first-principle calculations demand substantial computational resources\u0000and it is difficult to simulate large structures. This study introduces an\u0000alternative approach utilizing hybrid Monte-Carlo / Molecular Dynamics (MC/MD)\u0000simulations to investigate the surface composition of Ni-Mo alloys. We report\u0000the development of an optimized Embedded-Atom Method (EAM) potential\u0000specifically for Ni-Mo alloys, carefully parameterized using empirical lattice\u0000constants and formation energies of elemental and face-centered cubic (FCC)\u0000Ni-Mo solid solution alloys. The reliability of the EAM potential is\u0000corroborated via the evaluation of equations of state, with a particular focus\u0000on reproducing structural properties. Utilizing this validated potential, MC/MD\u0000simulations were performed to understand the depth-wise variations in the\u0000compositions of Ni-Mo alloy nanoparticles and extended surfaces. These\u0000simulations reveal a preferential segregation of nickel on surface, and\u0000molybdenum in sub-surface layer. Due to this preferential segregation, it is\u0000imperative to consider surface segregation while tailoring the surface\u0000properties for targeted applications.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigate the non-Hermitian Su-Schrieffer-Heeger (SSH) model on Bethe lattice, revealing a novel localization phenomenon coined inner non-Hermitian skin effect. This effect is featured by the localization of all eigenstates within the bulk of the lattice, diverging from the conventional skin effect observed in general non-Hermitian systems. The analytical treatment of the model demonstrates that the Hamiltonian can be decoupled into a series of one-dimensional chains, with one end fixed at the bottom boundary while the other ends positioned at varying generations within the bulk. This configuration leads to the emergence of the inner non-Hermitian skin effect, which is further validated by performing circuit simulations. Our findings provide new insights into the interplay between non-Hermitian physics and the self-similar structure on Bethe lattice.
{"title":"Inner non-Hermitian skin effect on Bethe lattice","authors":"Junsong Sun, Chang-An Li, Shiping Feng, Huaiming Guo","doi":"arxiv-2409.07117","DOIUrl":"https://doi.org/arxiv-2409.07117","url":null,"abstract":"We investigate the non-Hermitian Su-Schrieffer-Heeger (SSH) model on Bethe\u0000lattice, revealing a novel localization phenomenon coined inner non-Hermitian\u0000skin effect. This effect is featured by the localization of all eigenstates\u0000within the bulk of the lattice, diverging from the conventional skin effect\u0000observed in general non-Hermitian systems. The analytical treatment of the\u0000model demonstrates that the Hamiltonian can be decoupled into a series of\u0000one-dimensional chains, with one end fixed at the bottom boundary while the\u0000other ends positioned at varying generations within the bulk. This\u0000configuration leads to the emergence of the inner non-Hermitian skin effect,\u0000which is further validated by performing circuit simulations. Our findings\u0000provide new insights into the interplay between non-Hermitian physics and the\u0000self-similar structure on Bethe lattice.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although plasmons and phonons are the collective excitations that govern the low-energy physics of doped semiconductors, their nonadiabatic hybridization and mutual screening have not been studied from first principles. We achieve this goal by transforming the Dyson equation to the frequency-independent dynamical matrix of an equivalent damped oscillator. Calculations on doped GaAs and TiO2 agree well with available Raman data and await immediate experimental confirmation from infrared, neutron, electron-energy-loss, and angle-resolved photoemission spectroscopies.
{"title":"Plasmon-Phonon Hybridization in Doped Semiconductors from First Principles","authors":"Jae-Mo Lihm, Cheol-Hwan Park","doi":"arxiv-2409.07393","DOIUrl":"https://doi.org/arxiv-2409.07393","url":null,"abstract":"Although plasmons and phonons are the collective excitations that govern the\u0000low-energy physics of doped semiconductors, their nonadiabatic hybridization\u0000and mutual screening have not been studied from first principles. We achieve\u0000this goal by transforming the Dyson equation to the frequency-independent\u0000dynamical matrix of an equivalent damped oscillator. Calculations on doped GaAs\u0000and TiO2 agree well with available Raman data and await immediate experimental\u0000confirmation from infrared, neutron, electron-energy-loss, and angle-resolved\u0000photoemission spectroscopies.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"184 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baoru Pan, Pan Zhou, Pengbo Lyu, Huaping Xiao, Xuejuan Yang, Lizhong Sun
Two-dimensional (2D) altermagnetism was recently proposed to be attainable in twisted antiferromagnetic bilayers providing an experimentally feasible approach to realize it in 2D materials. Nevertheless, a comprehensive understanding of the mechanism governing the appearance of altermagnetism in bilayer systems is still absent. In present letter, we address this gap by introducing a general stacking theory (GST) as a key condition for the emergence of altermagnetism in bilayer systems. The GST provides straightforward criteria to predict whether a bilayer demonstrates altermagnetic spin splitting, solely based on the layer groups of the composing monolayers. According to the GST, only seven point groups of bilayers facilitate the emergence of altermagnetism. It is revealed that, beyond the previously proposed antiferromagnetic twisted vdW stacking, altermagnetism can even emerge in bilayers formed through the symmetrically restricted direct stacking of two monolayers. By combining the GST and first-principles calculations, we present illustrative examples of bilayers demonstrating altermagnetism. Our work establishes a robust framework for designing diverse bilayer systems with altermagnetism, thereby opening up new avenues for both fundamental research and practical applications in this field.
{"title":"General Stacking Theory for Altermagnetism in Bilayer Systems","authors":"Baoru Pan, Pan Zhou, Pengbo Lyu, Huaping Xiao, Xuejuan Yang, Lizhong Sun","doi":"arxiv-2409.06964","DOIUrl":"https://doi.org/arxiv-2409.06964","url":null,"abstract":"Two-dimensional (2D) altermagnetism was recently proposed to be attainable in\u0000twisted antiferromagnetic bilayers providing an experimentally feasible\u0000approach to realize it in 2D materials. Nevertheless, a comprehensive\u0000understanding of the mechanism governing the appearance of altermagnetism in\u0000bilayer systems is still absent. In present letter, we address this gap by\u0000introducing a general stacking theory (GST) as a key condition for the\u0000emergence of altermagnetism in bilayer systems. The GST provides\u0000straightforward criteria to predict whether a bilayer demonstrates\u0000altermagnetic spin splitting, solely based on the layer groups of the composing\u0000monolayers. According to the GST, only seven point groups of bilayers\u0000facilitate the emergence of altermagnetism. It is revealed that, beyond the\u0000previously proposed antiferromagnetic twisted vdW stacking, altermagnetism can\u0000even emerge in bilayers formed through the symmetrically restricted direct\u0000stacking of two monolayers. By combining the GST and first-principles\u0000calculations, we present illustrative examples of bilayers demonstrating\u0000altermagnetism. Our work establishes a robust framework for designing diverse\u0000bilayer systems with altermagnetism, thereby opening up new avenues for both\u0000fundamental research and practical applications in this field.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. K. Avetissian, H. H. Matevosyan, G. F. Mkrtchian
In this work, we present a microscopic quantum theory that elucidates the nonlinear-nonperturbative optical response of biased bilayer graphene subjected to a bichromatic strong laser fields. This response is analyzed using a four-band Hamiltonian derived from ab-initio calculations. For the laser-stimulated dynamics, we employ structure gauge-invariant evolutionary equations to accurately describe the evolution of the single-particle density matrix across the entire Brillouin zone. The resonant generation of electron-hole pairs by the high-frequency component of the field, combined with the induction of high-order harmonic generation (HHG) and high-order wave mixing (HWM) by the strong low-frequency field component, leads to significant alterations in the HWM and HHG spectra. These changes are driven by the effects of Berry curvature and the shift vector, which modify the relative contributions of interband and intraband channels, thereby fundamentally reshaping the radiation spectra at high-order frequency multiplication.
{"title":"Berry curvature and shift vector effects at high-order wave mixing in biased bilayer graphene","authors":"H. K. Avetissian, H. H. Matevosyan, G. F. Mkrtchian","doi":"arxiv-2409.06269","DOIUrl":"https://doi.org/arxiv-2409.06269","url":null,"abstract":"In this work, we present a microscopic quantum theory that elucidates the\u0000nonlinear-nonperturbative optical response of biased bilayer graphene subjected\u0000to a bichromatic strong laser fields. This response is analyzed using a\u0000four-band Hamiltonian derived from ab-initio calculations. For the\u0000laser-stimulated dynamics, we employ structure gauge-invariant evolutionary\u0000equations to accurately describe the evolution of the single-particle density\u0000matrix across the entire Brillouin zone. The resonant generation of\u0000electron-hole pairs by the high-frequency component of the field, combined with\u0000the induction of high-order harmonic generation (HHG) and high-order wave\u0000mixing (HWM) by the strong low-frequency field component, leads to significant\u0000alterations in the HWM and HHG spectra. These changes are driven by the effects\u0000of Berry curvature and the shift vector, which modify the relative\u0000contributions of interband and intraband channels, thereby fundamentally\u0000reshaping the radiation spectra at high-order frequency multiplication.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flavio Ronetti, Bruno Bertin-Johannet, Jérôme Rech, Thibaut Jonckheere, Benoît Grémaud, Laurent Raymond, Thierry Martin
We propose a source of purely electronic energy-entangled states implemented in a solid-state system with potential applications in quantum information protocols based on electron flying qubits. The proposed device relies on the standard tools of Electron Quantum Optics (EQO) and exploits entanglement of the Cooper pairs of a BCS superconductor. The latter is coupled via an adjustable quantum point contact to two opposite spin polarized electron wave-guides, which are driven by trains of Lorentzian pulses. This specific choice for the drive is crucial to inject purely electronic entangled-states devoid of spurious electron-hole pairs. In the Andreev regime, a perturbative calculation in the tunnel coupling confirms that entangled electrons states (EES) are generated at the output of the normal side. We introduce a quantity related to charge current cross-correlations which allows one to verify experimentally the entangled nature of the emitted state.
{"title":"Periodic source of energy-entangled electrons in helical states coupled to a BCS superconductor","authors":"Flavio Ronetti, Bruno Bertin-Johannet, Jérôme Rech, Thibaut Jonckheere, Benoît Grémaud, Laurent Raymond, Thierry Martin","doi":"arxiv-2409.06591","DOIUrl":"https://doi.org/arxiv-2409.06591","url":null,"abstract":"We propose a source of purely electronic energy-entangled states implemented\u0000in a solid-state system with potential applications in quantum information\u0000protocols based on electron flying qubits. The proposed device relies on the\u0000standard tools of Electron Quantum Optics (EQO) and exploits entanglement of\u0000the Cooper pairs of a BCS superconductor. The latter is coupled via an\u0000adjustable quantum point contact to two opposite spin polarized electron\u0000wave-guides, which are driven by trains of Lorentzian pulses. This specific\u0000choice for the drive is crucial to inject purely electronic entangled-states\u0000devoid of spurious electron-hole pairs. In the Andreev regime, a perturbative\u0000calculation in the tunnel coupling confirms that entangled electrons states\u0000(EES) are generated at the output of the normal side. We introduce a quantity\u0000related to charge current cross-correlations which allows one to verify\u0000experimentally the entangled nature of the emitted state.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The interplay between magnetism and strong electron correlation in magnetic materials discerns a variety of intriguing topological features. Here, we report a systematic investigation of the magnetic, thermodynamic, and electrical transport properties in NdGaSi single crystals. The magnetic measurements reveal a magnetic ordering below T_N (11 K), with spins aligning antiferromagnetically in-plane, and it orders ferromagnetically (FM) out-of-plane. The longitudinal resistivity data and heat capacity exhibit a significant anomaly as a consequence of the magnetic ordering at TN. The magnetoresistance study shows significantly different behavior when measured along either direction, resulting from the complex nature of the magnetic structure, stemming from complete saturation of moments in one direction and subsequent spin flop transitions in the other. Remarkably, we have also noticed an unusual anisotropic anomalous Hall response. We have observed a giant anomalous Hall conductivity (AHC) of 1730 ohm-1 cm-1 and 490 ohm-1 cm-1 at 2 K, with B // [001] and B // [100], respectively. Our scaling analysis of AHC reveals that the anomalous Hall effect in the studied compound is dominated by the Berry phase-driven intrinsic mechanism. These astonishing findings in NdGaSi open up new possibilities for antiferromagnetic spintronics in rare-earth-based intermetallic compounds.
{"title":"Giant anisotropic anomalous Hall effect in antiferromagnetic topological metal NdGaSi","authors":"Anyesh Saraswati, Sudipta Chatterjee, Nitesh Kumar","doi":"arxiv-2409.06250","DOIUrl":"https://doi.org/arxiv-2409.06250","url":null,"abstract":"The interplay between magnetism and strong electron correlation in magnetic\u0000materials discerns a variety of intriguing topological features. Here, we\u0000report a systematic investigation of the magnetic, thermodynamic, and\u0000electrical transport properties in NdGaSi single crystals. The magnetic\u0000measurements reveal a magnetic ordering below T_N (11 K), with spins aligning\u0000antiferromagnetically in-plane, and it orders ferromagnetically (FM)\u0000out-of-plane. The longitudinal resistivity data and heat capacity exhibit a\u0000significant anomaly as a consequence of the magnetic ordering at TN. The\u0000magnetoresistance study shows significantly different behavior when measured\u0000along either direction, resulting from the complex nature of the magnetic\u0000structure, stemming from complete saturation of moments in one direction and\u0000subsequent spin flop transitions in the other. Remarkably, we have also noticed\u0000an unusual anisotropic anomalous Hall response. We have observed a giant\u0000anomalous Hall conductivity (AHC) of 1730 ohm-1 cm-1 and 490 ohm-1 cm-1 at 2 K,\u0000with B // [001] and B // [100], respectively. Our scaling analysis of AHC\u0000reveals that the anomalous Hall effect in the studied compound is dominated by\u0000the Berry phase-driven intrinsic mechanism. These astonishing findings in\u0000NdGaSi open up new possibilities for antiferromagnetic spintronics in\u0000rare-earth-based intermetallic compounds.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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