Rodrigo Cezar de Campos Ferreira, Amandeep Sagwal, Jiří Doležal, Sofia Canola, Pablo Merino, Tomáš Neuman, Martin Švec
Single-molecule tip-enhanced Raman spectroscopy (TERS) under ultra-high vacuum (UHV) and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecting spin states in open-shell molecular configurations is yet unexplored. Here we use the tip of a scanning probe microscope to lift a perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecule from a metal surface to bring it into an open-shell spin one-half anionic state. We reveal a correlation between the appearance of a Kondo resonance in the differential conductance spectroscopy and concurrent characteristic changes captured by the TERS measurements. Through a detailed investigation of various adsorbed and tip-contacted PTCDA scenarios, we infer that the Raman scattering on the suspended PTCDA is resonant with a higher excited state. Theoretical simulation of the vibrational spectra enables a precise assignment of the individual TERS peaks to high-symmetry Ag modes, including the fingerprints of the observed spin state. These findings highlight the potential of TERS in capturing complex interactions between charge, spin, and photophysical properties in nanoscale molecular systems, and suggest a pathway for designing spin-optical devices using organic molecules.
{"title":"Resonant TERS of a Single-Molecule Kondo System","authors":"Rodrigo Cezar de Campos Ferreira, Amandeep Sagwal, Jiří Doležal, Sofia Canola, Pablo Merino, Tomáš Neuman, Martin Švec","doi":"arxiv-2310.12546","DOIUrl":"https://doi.org/arxiv-2310.12546","url":null,"abstract":"Single-molecule tip-enhanced Raman spectroscopy (TERS) under ultra-high\u0000vacuum (UHV) and cryogenic conditions enables exploration of the relations\u0000between the adsorption geometry, electronic state, and vibrational fingerprints\u0000of individual molecules. TERS capability of reflecting spin states in\u0000open-shell molecular configurations is yet unexplored. Here we use the tip of a\u0000scanning probe microscope to lift a perylene-3,4,9,10-tetracarboxylic\u0000dianhydride (PTCDA) molecule from a metal surface to bring it into an\u0000open-shell spin one-half anionic state. We reveal a correlation between the\u0000appearance of a Kondo resonance in the differential conductance spectroscopy\u0000and concurrent characteristic changes captured by the TERS measurements.\u0000Through a detailed investigation of various adsorbed and tip-contacted PTCDA\u0000scenarios, we infer that the Raman scattering on the suspended PTCDA is\u0000resonant with a higher excited state. Theoretical simulation of the vibrational\u0000spectra enables a precise assignment of the individual TERS peaks to\u0000high-symmetry Ag modes, including the fingerprints of the observed spin state.\u0000These findings highlight the potential of TERS in capturing complex\u0000interactions between charge, spin, and photophysical properties in nanoscale\u0000molecular systems, and suggest a pathway for designing spin-optical devices\u0000using organic molecules.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522547","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}
Alisher Duspayev, Ryan Cardman, David A. Anderson, Georg Raithel
We prepare and analyze Rydberg states with orbital quantum numbers $ell le 6$ using three-optical-photon electromagnetically-induced transparency (EIT) and radio-frequency (RF) dressing, and employ the high-$ell$ states in electric-field sensing. Rubidium-85 atoms in a room-temperature vapor cell are first promoted into the $25F_{5/2}$ state via Rydberg-EIT with three infrared laser beams. Two RF dressing fields then (near-)resonantly couple $25 ell$ Rydberg states with high $ell$. The dependence of the RF-dressed Rydberg-state level structure on RF powers, RF and laser frequencies is characterized using EIT. Furthermore, we discuss the principles of DC-electric-field sensing using high-$ell$ Rydberg states, and experimentally demonstrate the method using test electric fields of $lesssim$~50~V/m induced via photo-illumination of the vapor-cell wall. We measure the highly nonlinear dependence of the DC-electric-field strength on the power of the photo-illumination laser. Numerical calculations, which reproduce our experimental observations well, elucidate the underlying physics. Our study is relevant to high-precision spectroscopy of high-$ell$ Rydberg states, Rydberg-atom-based electric-field sensing, and plasma electric-field diagnostics.
我们利用三光光子电致透明(EIT)和射频(RF)处理技术制备并分析了轨道量子数为$ well le6$的里德伯态，并将其用于电场传感。利用三束红外激光束，通过Rydberg-EIT将室温蒸汽池中的铷-85原子提升到$25F_{5/2}$态。两个射频处理场然后(近)共振耦合$25 well $Rydberg态和高$ well $。利用eit分析了射频修饰的里德堡态能级结构与射频功率、射频和激光频率的关系。此外，我们还讨论了利用高阱里德堡态进行直流电场传感的原理，并通过实验证明了利用光照射蒸汽电池壁产生的小于50 V/m的测试电场的方法。我们测量了直流电场强度对光照明激光器功率的高度非线性依赖关系。数值计算很好地再现了我们的实验观察，阐明了潜在的物理学。我们的研究涉及高阱里德堡态的高精度光谱、基于里德堡原子的电场传感和等离子体电场诊断。
{"title":"High-angular-momentum Rydberg states in a room-temperature vapor cell for DC electric-field sensing","authors":"Alisher Duspayev, Ryan Cardman, David A. Anderson, Georg Raithel","doi":"arxiv-2310.10542","DOIUrl":"https://doi.org/arxiv-2310.10542","url":null,"abstract":"We prepare and analyze Rydberg states with orbital quantum numbers $ell le\u00006$ using three-optical-photon electromagnetically-induced transparency (EIT)\u0000and radio-frequency (RF) dressing, and employ the high-$ell$ states in\u0000electric-field sensing. Rubidium-85 atoms in a room-temperature vapor cell are\u0000first promoted into the $25F_{5/2}$ state via Rydberg-EIT with three infrared\u0000laser beams. Two RF dressing fields then (near-)resonantly couple $25 ell$\u0000Rydberg states with high $ell$. The dependence of the RF-dressed Rydberg-state\u0000level structure on RF powers, RF and laser frequencies is characterized using\u0000EIT. Furthermore, we discuss the principles of DC-electric-field sensing using\u0000high-$ell$ Rydberg states, and experimentally demonstrate the method using\u0000test electric fields of $lesssim$~50~V/m induced via photo-illumination of the\u0000vapor-cell wall. We measure the highly nonlinear dependence of the\u0000DC-electric-field strength on the power of the photo-illumination laser.\u0000Numerical calculations, which reproduce our experimental observations well,\u0000elucidate the underlying physics. Our study is relevant to high-precision\u0000spectroscopy of high-$ell$ Rydberg states, Rydberg-atom-based electric-field\u0000sensing, and plasma electric-field diagnostics.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522545","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}
Alexander V. Oleynichenko, Yuriy V. Lomachuk, Daniil A. Maltsev, Nikolai S. Mosyagin, Vera M. Shakhova, Andrei Zaitsevskii, Anatoly V. Titov
A method to simulate local properties and processes in crystals with impurities via constructing cluster models within the frame of the compound-tunable embedding potential (CTEP) and highly-accurate {it ab initio} relativistic molecular-type electronic structure calculations is developed and applied to the Ce and Th-doped yttrium orthophosphate crystals, YPO$_4$, having xenotime structure. Two embedded cluster models are considered, the "minimal" one, YO$_8$@CTEP$_{rm min}$, consisting of the central Y$^{3+}$ cation and its first coordination sphere of eight O$^{2-}$ anions (i.~e. with broken P--O bonds), and its extended counterpart, Y(PO$_4$)$_6$@CTEP$_{rm ext}$, implying the full treatment of all atoms of the PO$_4^{3-}$ anions nearest to the central Y$^{3+}$ cation. CTEP$_{rm min,ext}$ denote here the corresponding cluster environment described within the CTEP method. The relativistic Fock-space coupled cluster (FS RCC) theory is applied to the minimal cluster model to study electronic excitations localized on Ce$^{3+}$ and Th$^{3+}$ impurity ions. Calculated transition energies for the cerium-doped xenotime are in a good agreement with the available experimental data (mean absolute deviation of ca.0.3 eV for $4f{to}5d$ type transitions). For the thorium-doped crystal the picture of electronic states is predicted to be quite complicated, the ground state is expected to be of the $6d$ character. The uncertainty for the excitation energies of thorium-doped xenotime is estimated to be within 0.35 eV. Radiative lifetimes of excited states are calculated at the FS RCC level for both doped crystals. The calculated lifetime of the lowest $5d$ state of Ce$^{3+}$ differs from the experimentally measured one by no more than twice.
{"title":"Compound-tunable embedding potential method to model local electronic excitations on $f$-element ions in solids: Pilot relativistic coupled cluster study of Ce and Th impurities in yttrium orthophosphate, YPO$_4$","authors":"Alexander V. Oleynichenko, Yuriy V. Lomachuk, Daniil A. Maltsev, Nikolai S. Mosyagin, Vera M. Shakhova, Andrei Zaitsevskii, Anatoly V. Titov","doi":"arxiv-2310.09240","DOIUrl":"https://doi.org/arxiv-2310.09240","url":null,"abstract":"A method to simulate local properties and processes in crystals with\u0000impurities via constructing cluster models within the frame of the\u0000compound-tunable embedding potential (CTEP) and highly-accurate {it ab initio}\u0000relativistic molecular-type electronic structure calculations is developed and\u0000applied to the Ce and Th-doped yttrium orthophosphate crystals, YPO$_4$, having\u0000xenotime structure. Two embedded cluster models are considered, the \"minimal\"\u0000one, YO$_8$@CTEP$_{rm min}$, consisting of the central Y$^{3+}$ cation and its\u0000first coordination sphere of eight O$^{2-}$ anions (i.~e. with broken P--O\u0000bonds), and its extended counterpart, Y(PO$_4$)$_6$@CTEP$_{rm ext}$, implying\u0000the full treatment of all atoms of the PO$_4^{3-}$ anions nearest to the\u0000central Y$^{3+}$ cation. CTEP$_{rm min,ext}$ denote here the corresponding\u0000cluster environment described within the CTEP method. The relativistic\u0000Fock-space coupled cluster (FS RCC) theory is applied to the minimal cluster\u0000model to study electronic excitations localized on Ce$^{3+}$ and Th$^{3+}$\u0000impurity ions. Calculated transition energies for the cerium-doped xenotime are\u0000in a good agreement with the available experimental data (mean absolute\u0000deviation of ca.0.3 eV for $4f{to}5d$ type transitions). For the thorium-doped\u0000crystal the picture of electronic states is predicted to be quite complicated,\u0000the ground state is expected to be of the $6d$ character. The uncertainty for\u0000the excitation energies of thorium-doped xenotime is estimated to be within\u00000.35 eV. Radiative lifetimes of excited states are calculated at the FS RCC\u0000level for both doped crystals. The calculated lifetime of the lowest $5d$ state\u0000of Ce$^{3+}$ differs from the experimentally measured one by no more than\u0000twice.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522617","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}
Enguerran Belles, Franck Rabilloud, Alexander I. Kuleff, Victor Despré
Correlation-driven charge migration initiated by inner-valence ionization leading to the population of the correlation bands of alkyne chains containing between 4 and 12 carbon atoms is explored through ab initio simulations. Scaling laws are observed, both for the timescale of the charge migration and for the slope of the density of states of the correlation bands. Those can be used for predicting the relaxation time scale in much larger systems from the same molecular family and for finding promising candidates for the development of attochemistry scheme taking advantages of the specificity of the dynamics in correlation bands of molecules.
{"title":"Size effect in correlation-driven charge migration in correlation bands of alkyne chains","authors":"Enguerran Belles, Franck Rabilloud, Alexander I. Kuleff, Victor Despré","doi":"arxiv-2310.08159","DOIUrl":"https://doi.org/arxiv-2310.08159","url":null,"abstract":"Correlation-driven charge migration initiated by inner-valence ionization\u0000leading to the population of the correlation bands of alkyne chains containing\u0000between 4 and 12 carbon atoms is explored through ab initio simulations.\u0000Scaling laws are observed, both for the timescale of the charge migration and\u0000for the slope of the density of states of the correlation bands. Those can be\u0000used for predicting the relaxation time scale in much larger systems from the\u0000same molecular family and for finding promising candidates for the development\u0000of attochemistry scheme taking advantages of the specificity of the dynamics in\u0000correlation bands of molecules.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522622","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}
Nahid Sadat Riyahi, Mohammad Goli, Shant Shahbazian
The multi-component density functional theory is faced with the challenge of capturing various types of inter- and intra-particle exchange-correlation effects beyond those introduced by the conventional electronic exchange-correlation functionals. Herein, we focus on evaluating the electron-proton/muon correlation functionals appearing in molecular/condensed-phase systems where a proton/muon is treated as a quantum particle on equal footing with electrons, beyond the Born-Oppenheimer paradigm. Five recently developed local correlation functionals, i.e. the epc series and e$mu$c-1, are selected and their performances are analyzed by employing a two-particle model that includes an electron and a positively charged particle (PCP) with a variable mass, interacting through Coulombic forces, within a double harmonic trap. Using the Kohn-Sham (KS) inversion procedure, the exact two-component KS characterization of the model is deduced and its properties are compared to those derived from the considered functionals. The analysis demonstrates that these local functionals achieve their original parameterization objectives to reproduce the one-PCP densities and the electron-PCP correlation energies, but all fall short of reproducing the underlying PCP correlation potentials correctly. Moreover, a comprehensive error analysis reveals that the density-driven errors have a non-negligible contribution to the success of the considered functionals. Overall, the study shows the strengths as well as shortcomings of the considered functionals hopefully paving the way for designing more robust functionals in the future.
{"title":"Quantifying errors of the electron-proton/muon correlation functionals through the Kohn-Sham inversion of a two-component model system","authors":"Nahid Sadat Riyahi, Mohammad Goli, Shant Shahbazian","doi":"arxiv-2310.02397","DOIUrl":"https://doi.org/arxiv-2310.02397","url":null,"abstract":"The multi-component density functional theory is faced with the challenge of\u0000capturing various types of inter- and intra-particle exchange-correlation\u0000effects beyond those introduced by the conventional electronic\u0000exchange-correlation functionals. Herein, we focus on evaluating the\u0000electron-proton/muon correlation functionals appearing in\u0000molecular/condensed-phase systems where a proton/muon is treated as a quantum\u0000particle on equal footing with electrons, beyond the Born-Oppenheimer paradigm.\u0000Five recently developed local correlation functionals, i.e. the epc series and\u0000e$mu$c-1, are selected and their performances are analyzed by employing a\u0000two-particle model that includes an electron and a positively charged particle\u0000(PCP) with a variable mass, interacting through Coulombic forces, within a\u0000double harmonic trap. Using the Kohn-Sham (KS) inversion procedure, the exact\u0000two-component KS characterization of the model is deduced and its properties\u0000are compared to those derived from the considered functionals. The analysis\u0000demonstrates that these local functionals achieve their original\u0000parameterization objectives to reproduce the one-PCP densities and the\u0000electron-PCP correlation energies, but all fall short of reproducing the\u0000underlying PCP correlation potentials correctly. Moreover, a comprehensive\u0000error analysis reveals that the density-driven errors have a non-negligible\u0000contribution to the success of the considered functionals. Overall, the study\u0000shows the strengths as well as shortcomings of the considered functionals\u0000hopefully paving the way for designing more robust functionals in the future.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522612","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}
Mariyam Fatima, Holger S. P. Müller, Oliver Zingsheim, Frank Lewen, Víctor M. Rivilla, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Stephan Schlemmer
Isobutene ((CH$_3$)$_2$C=CH$_2$) is one of the four isomers of butene (C$_4$H$_8$). Given the detection of propene (CH$_3$CH=CH$_2$) toward TMC-1, and also in the warmer environment of the solar-type protostellar system IRAS 16293$-$2422, one of the next alkenes, isobutene, is a promising candidate to be searched for in space. We aim to extend the limited line lists of the main isotopologue of isobutene from the microwave to the millimetre region in order to obtain a highly precise set of rest frequencies and to facilitate its detection in the interstellar medium. We investigated the rotational spectrum of isobutene in the 35$-$370 GHz range using absorption spectroscopy at room temperature. Quantum-chemical calculations were carried out to evaluate vibrational frequencies. We determined new or improved spectroscopic parameters for isobutene up to a sixth-order distortion constant. These new results enabled its detection in the G+0.693 molecular cloud for the first time, where propene was also recently found. The propene to isobutene column density ratio was determined to be about 3:1. The observed spectroscopic parameters for isobutene are sufficiently accurate that calculated transition frequencies should be reliable up to 700 GHz. This will further help in observing this alkene in other, warmer regions of the ISM.
{"title":"Millimetre and submillimetre spectroscopy of isobutene and its detection in the molecular cloud G+0.693","authors":"Mariyam Fatima, Holger S. P. Müller, Oliver Zingsheim, Frank Lewen, Víctor M. Rivilla, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Stephan Schlemmer","doi":"arxiv-2309.17236","DOIUrl":"https://doi.org/arxiv-2309.17236","url":null,"abstract":"Isobutene ((CH$_3$)$_2$C=CH$_2$) is one of the four isomers of butene\u0000(C$_4$H$_8$). Given the detection of propene (CH$_3$CH=CH$_2$) toward TMC-1,\u0000and also in the warmer environment of the solar-type protostellar system IRAS\u000016293$-$2422, one of the next alkenes, isobutene, is a promising candidate to\u0000be searched for in space. We aim to extend the limited line lists of the main\u0000isotopologue of isobutene from the microwave to the millimetre region in order\u0000to obtain a highly precise set of rest frequencies and to facilitate its\u0000detection in the interstellar medium. We investigated the rotational spectrum\u0000of isobutene in the 35$-$370 GHz range using absorption spectroscopy at room\u0000temperature. Quantum-chemical calculations were carried out to evaluate\u0000vibrational frequencies. We determined new or improved spectroscopic parameters\u0000for isobutene up to a sixth-order distortion constant. These new results\u0000enabled its detection in the G+0.693 molecular cloud for the first time, where\u0000propene was also recently found. The propene to isobutene column density ratio\u0000was determined to be about 3:1. The observed spectroscopic parameters for\u0000isobutene are sufficiently accurate that calculated transition frequencies\u0000should be reliable up to 700 GHz. This will further help in observing this\u0000alkene in other, warmer regions of the ISM.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522548","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}
Mikhail Maslov, Georgios M. Koutentakis, Mateja Hrast, Oliver H. Heckl, Mikhail Lemeshko
The interaction of molecules with the orbital angular momentum of light has long been argued to benefit structural studies and quantum control of molecular ensembles. We derive a general description of the light-matter interaction in terms of the coupling between spherical gradients of the electric field and an effective molecular charge density that exactly reproduces molecular multipole moments. Our model can accommodate for an arbitrary complexity of the molecular structure and is applicable to any electric field, with the exception of tightly focused beams. Within this framework, we derive the general mechanism of angular momentum exchange between the spin and orbital angular momenta of light, molecular rotation and its center-of-mass motion. We demonstrate that vortex beams strongly enhance certain ro-vibrational transitions that are considered forbidden in the case of a non-helical light. Finally, we discuss the experimental requirements for the observation of novel transitions in state-of-the-art spatially-resolved spectroscopy measurements.
{"title":"Charge density model for the interaction of molecules with vortex beams","authors":"Mikhail Maslov, Georgios M. Koutentakis, Mateja Hrast, Oliver H. Heckl, Mikhail Lemeshko","doi":"arxiv-2310.00095","DOIUrl":"https://doi.org/arxiv-2310.00095","url":null,"abstract":"The interaction of molecules with the orbital angular momentum of light has\u0000long been argued to benefit structural studies and quantum control of molecular\u0000ensembles. We derive a general description of the light-matter interaction in\u0000terms of the coupling between spherical gradients of the electric field and an\u0000effective molecular charge density that exactly reproduces molecular multipole\u0000moments. Our model can accommodate for an arbitrary complexity of the molecular\u0000structure and is applicable to any electric field, with the exception of\u0000tightly focused beams. Within this framework, we derive the general mechanism\u0000of angular momentum exchange between the spin and orbital angular momenta of\u0000light, molecular rotation and its center-of-mass motion. We demonstrate that\u0000vortex beams strongly enhance certain ro-vibrational transitions that are\u0000considered forbidden in the case of a non-helical light. Finally, we discuss\u0000the experimental requirements for the observation of novel transitions in\u0000state-of-the-art spatially-resolved spectroscopy measurements.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522543","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}
Viktor Mandrolko, Guillaume Castanet, Sergii Burian, Yaroslav Grosu, Liudmyla Klochko, David Lacroix, Mykola Isaiev
Understanding the physics of a three-phase contact line between gas, liquid, and solid is important for numerous applications. At the macroscale, the three-phase contact line response to an external force action is often characterized by a contact angle hysteresis, and several models are presented in the literature for its description. Yet, there is still a need for more information about such model applications at the nanoscale. In this study, a molecular dynamics approach was used to investigate the shape of a liquid droplet under an external force for different wetting regimes. In addition, an analytic model for describing the droplet shape was developed. It gives us the possibility to evaluate the receding and advancing wetting angle accurately. With our modeling, we found that the interplay between capillary forces and viscous forces is crucial to characterize the droplet shape at the nanoscale. In this frame, the importance of the rolling movement of the interface between liquid and vapor was pointed out. We also demonstrate that in the range of the external forces when capillary forces are most significant compared to others, hysteresis is well described by the macroscale Cox-Voinov model.
{"title":"Contact angle hysteresis at the nanoscale","authors":"Viktor Mandrolko, Guillaume Castanet, Sergii Burian, Yaroslav Grosu, Liudmyla Klochko, David Lacroix, Mykola Isaiev","doi":"arxiv-2309.14986","DOIUrl":"https://doi.org/arxiv-2309.14986","url":null,"abstract":"Understanding the physics of a three-phase contact line between gas, liquid,\u0000and solid is important for numerous applications. At the macroscale, the\u0000three-phase contact line response to an external force action is often\u0000characterized by a contact angle hysteresis, and several models are presented\u0000in the literature for its description. Yet, there is still a need for more\u0000information about such model applications at the nanoscale. In this study, a\u0000molecular dynamics approach was used to investigate the shape of a liquid\u0000droplet under an external force for different wetting regimes. In addition, an\u0000analytic model for describing the droplet shape was developed. It gives us the\u0000possibility to evaluate the receding and advancing wetting angle accurately.\u0000With our modeling, we found that the interplay between capillary forces and\u0000viscous forces is crucial to characterize the droplet shape at the nanoscale.\u0000In this frame, the importance of the rolling movement of the interface between\u0000liquid and vapor was pointed out. We also demonstrate that in the range of the\u0000external forces when capillary forces are most significant compared to others,\u0000hysteresis is well described by the macroscale Cox-Voinov model.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"320 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522620","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}
Divyam Neer Verma, KV Chinmaya, Moumita Ghosh, Jan Heck, G Mohan Rao, Sonia Contera, Siddharth Ghosh
In the domain of single-molecule dynamics, we investigate the impact of electrostatic forces on molecular motion. Our study delves into the interplay between quantum mechanics and electrostatic interactions, resulting in trajectories reminiscent of planetary motion and gravity-assisted acceleration. By employing state-dependent diffusion and Green's functions, we establish a robust theoretical foundation that explains quantum control over molecules. We find that surface charge density critically influences diffusion coefficients, following linear scaling similar to Coulombic forces. Our research extends the range of observed diffusion coefficients, reaching up to 6000 $mutext{m}^2text{ms}^{-1}$. These findings have practical applications in materials science and molecular engineering. This study advances our understanding of molecular motion and highlights the potential for precise control over single-molecule dynamics through quantum manipulation-an exploration at the nanoscale.
{"title":"Single electron-controlled motions of single molecules","authors":"Divyam Neer Verma, KV Chinmaya, Moumita Ghosh, Jan Heck, G Mohan Rao, Sonia Contera, Siddharth Ghosh","doi":"arxiv-2310.09296","DOIUrl":"https://doi.org/arxiv-2310.09296","url":null,"abstract":"In the domain of single-molecule dynamics, we investigate the impact of\u0000electrostatic forces on molecular motion. Our study delves into the interplay\u0000between quantum mechanics and electrostatic interactions, resulting in\u0000trajectories reminiscent of planetary motion and gravity-assisted acceleration.\u0000By employing state-dependent diffusion and Green's functions, we establish a\u0000robust theoretical foundation that explains quantum control over molecules. We\u0000find that surface charge density critically influences diffusion coefficients,\u0000following linear scaling similar to Coulombic forces. Our research extends the\u0000range of observed diffusion coefficients, reaching up to 6000\u0000$mutext{m}^2text{ms}^{-1}$. These findings have practical applications in\u0000materials science and molecular engineering. This study advances our\u0000understanding of molecular motion and highlights the potential for precise\u0000control over single-molecule dynamics through quantum manipulation-an\u0000exploration at the nanoscale.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522626","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}
R. Barzaga, D. A. Garcia-Hernandez, S. Diaz-Tendero, S. Sadjadi, A. Manchado, M. Alcami, M. A. Gomez-Muñoz, T. Huertas-Roldan
Small metal-containing molecules have been detected and recognized as one of the hybrid species efficiently formed in space; especially in the circumstellar envelopes of evolved stars. It has been predicted also that more complex hybrid species like those formed by metals and fullerenes (metallofullerenes) could be present in such circumstellar environments. Recently, quantum-chemical simulations of metallofullerenes have shown that they are potential emitters contributing to the observed mid-IR spectra in the fullerene-rich circumstellar environments of different types of evolved stars. Here we present the individual simulated mid-IR (~5-50 um) spectra of twenty-eight metallofullerene species; both neutral and charged endo- and exohedral metallofullerenes for seven different metals (Li, Na, K, Ca, Mg, Ti, and Fe) have been considered. The changes induced by the metal-C60 interaction on the intensity and position of the spectral features are highlighted using charge density difference maps and electron density partitioning. Our calculations identify the fundamental IR spectral regions where, depending on the metal binding nature, there should be a major spectral contribution from each of the metallofullerenes. The metallofullerenes IR spectra are made publicly available to the astronomical community, especially James Webb Space Telescope users, for comparisons that could eventually lead to the detection of these species in space.
含有金属的小分子被发现并被认为是在太空中有效形成的杂交物种之一;尤其是在演化恒星的周围。据预测，在这样的星周环境中可能存在更复杂的杂合物种，比如由金属和富勒烯(金属富勒烯)形成的杂合物种。最近，金属富勒烯的量子化学模拟表明，它们是潜在的发射器，有助于在不同类型的演化恒星的富富勒烯环境中观测到的中红外光谱。在这里，我们给出了28种金属富勒烯的单个模拟中红外光谱(~5-50 μ m);研究了七种不同金属(Li, Na, K, Ca, Mg, Ti和Fe)的中性和带电的内、外面体金属富勒烯。利用电荷密度差图和电子密度划分，突出了金属- c60相互作用对光谱特征的强度和位置的变化。我们的计算确定了基本的红外光谱区域，根据金属结合的性质，每个金属富勒烯应该有主要的光谱贡献。金属富勒烯的红外光谱可以公开提供给天文学界，特别是詹姆斯·韦伯太空望远镜的用户，以进行比较，最终可能导致在太空中发现这些物种。
{"title":"Infrared spectral fingerprint of neutral and charged endo- and exohedral metallofullerenes","authors":"R. Barzaga, D. A. Garcia-Hernandez, S. Diaz-Tendero, S. Sadjadi, A. Manchado, M. Alcami, M. A. Gomez-Muñoz, T. Huertas-Roldan","doi":"arxiv-2309.11265","DOIUrl":"https://doi.org/arxiv-2309.11265","url":null,"abstract":"Small metal-containing molecules have been detected and recognized as one of\u0000the hybrid species efficiently formed in space; especially in the circumstellar\u0000envelopes of evolved stars. It has been predicted also that more complex hybrid\u0000species like those formed by metals and fullerenes (metallofullerenes) could be\u0000present in such circumstellar environments. Recently, quantum-chemical\u0000simulations of metallofullerenes have shown that they are potential emitters\u0000contributing to the observed mid-IR spectra in the fullerene-rich circumstellar\u0000environments of different types of evolved stars. Here we present the\u0000individual simulated mid-IR (~5-50 um) spectra of twenty-eight metallofullerene\u0000species; both neutral and charged endo- and exohedral metallofullerenes for\u0000seven different metals (Li, Na, K, Ca, Mg, Ti, and Fe) have been considered.\u0000The changes induced by the metal-C60 interaction on the intensity and position\u0000of the spectral features are highlighted using charge density difference maps\u0000and electron density partitioning. Our calculations identify the fundamental IR\u0000spectral regions where, depending on the metal binding nature, there should be\u0000a major spectral contribution from each of the metallofullerenes. The\u0000metallofullerenes IR spectra are made publicly available to the astronomical\u0000community, especially James Webb Space Telescope users, for comparisons that\u0000could eventually lead to the detection of these species in space.","PeriodicalId":501259,"journal":{"name":"arXiv - PHYS - Atomic and Molecular Clusters","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138522546","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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