Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054118
Pierre Nazé
The optimal protocols for the irreversible work achieve their maximum usefulness if their work fluctuations are the smallest ones. In this work, for classical and isothermal processes subjected to finite-time and weak drivings, I show that the optimal protocol for the irreversible work is the same for the variance of work. This conclusion is based on the fluctuation-dissipation relation $overline{W}=mathrm{ensuremath{Delta}}F+ensuremath{beta}{ensuremath{sigma}}_{W}^{2}/2$, extended now to finite-time and weak drivings. To illustrate it, I analyze a white-noise overdamped Brownian motion subjected to an anharmonic stiffening trap for fast processes. By contrast with the already known results in the literature for classical systems, the linear-response theory approach of the work probabilistic distribution is not a Gaussian reduction.
{"title":"Optimal work fluctuations for finite-time and weak processes","authors":"Pierre Nazé","doi":"10.1103/physreve.108.054118","DOIUrl":"https://doi.org/10.1103/physreve.108.054118","url":null,"abstract":"The optimal protocols for the irreversible work achieve their maximum usefulness if their work fluctuations are the smallest ones. In this work, for classical and isothermal processes subjected to finite-time and weak drivings, I show that the optimal protocol for the irreversible work is the same for the variance of work. This conclusion is based on the fluctuation-dissipation relation $overline{W}=mathrm{ensuremath{Delta}}F+ensuremath{beta}{ensuremath{sigma}}_{W}^{2}/2$, extended now to finite-time and weak drivings. To illustrate it, I analyze a white-noise overdamped Brownian motion subjected to an anharmonic stiffening trap for fast processes. By contrast with the already known results in the literature for classical systems, the linear-response theory approach of the work probabilistic distribution is not a Gaussian reduction.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283267","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}
Pub Date : 2023-11-13DOI: 10.1103/physreva.108.053312
Eduardo Ibarra-García-Padilla, Chunhan Feng, Giulio Pasqualetti, Simon Fölling, Richard T. Scalettar, Ehsan Khatami, Kaden R. A. Hazzard
We study the SU(3) symmetric Fermi-Hubbard model (FHM) in the square lattice at $1/3$-filling using numerically exact determinant quantum Monte Carlo and numerical linked-cluster expansion techniques. We present the different regimes of the model in the $Ttext{ensuremath{-}}U$ plane, which are characterized by local and short-range correlations, and capture signatures of the metal-insulator transition and magnetic crossovers. These signatures are detected as the temperature scales characterizing the rise of the compressibility, and an interaction-dependent change in the sign of the diagonal spin-spin correlation function. The analysis of the compressibility estimates the location of the metal-insulator quantum critical point at ${U}_{c}/tensuremath{sim}6$, and provides a temperature scale for observing Mott physics at finite $T$. Furthermore, from the analysis of the spin-spin correlation function we observe that for $U/tensuremath{gtrsim}6$ and $Tensuremath{sim}J=4{t}^{2}/U$ there is a development of a short-range two-sublattice (2SL) antiferromagnetic structure, as well as an emerging three-sublattice (3SL) antiferromagnetic structure as the temperature is lowered below $T/Jensuremath{lesssim}0.57$. This crossover from 2SL to 3SL magnetic ordering agrees with Heisenberg limit predictions, and has observable effects on the density of on-site pairs. Finally, we describe how the features of the regimes in the $Tensuremath{-}U$ plane can be explored with alkaline-earth-like atoms in optical lattices with currently achieved experimental techniques and temperatures. The results discussed in this paper provide a starting point for the exploration of the SU(3) FHM upon doping.
{"title":"Metal-insulator transition and magnetism of SU(3) fermions in the square lattice","authors":"Eduardo Ibarra-García-Padilla, Chunhan Feng, Giulio Pasqualetti, Simon Fölling, Richard T. Scalettar, Ehsan Khatami, Kaden R. A. Hazzard","doi":"10.1103/physreva.108.053312","DOIUrl":"https://doi.org/10.1103/physreva.108.053312","url":null,"abstract":"We study the SU(3) symmetric Fermi-Hubbard model (FHM) in the square lattice at $1/3$-filling using numerically exact determinant quantum Monte Carlo and numerical linked-cluster expansion techniques. We present the different regimes of the model in the $Ttext{ensuremath{-}}U$ plane, which are characterized by local and short-range correlations, and capture signatures of the metal-insulator transition and magnetic crossovers. These signatures are detected as the temperature scales characterizing the rise of the compressibility, and an interaction-dependent change in the sign of the diagonal spin-spin correlation function. The analysis of the compressibility estimates the location of the metal-insulator quantum critical point at ${U}_{c}/tensuremath{sim}6$, and provides a temperature scale for observing Mott physics at finite $T$. Furthermore, from the analysis of the spin-spin correlation function we observe that for $U/tensuremath{gtrsim}6$ and $Tensuremath{sim}J=4{t}^{2}/U$ there is a development of a short-range two-sublattice (2SL) antiferromagnetic structure, as well as an emerging three-sublattice (3SL) antiferromagnetic structure as the temperature is lowered below $T/Jensuremath{lesssim}0.57$. This crossover from 2SL to 3SL magnetic ordering agrees with Heisenberg limit predictions, and has observable effects on the density of on-site pairs. Finally, we describe how the features of the regimes in the $Tensuremath{-}U$ plane can be explored with alkaline-earth-like atoms in optical lattices with currently achieved experimental techniques and temperatures. The results discussed in this paper provide a starting point for the exploration of the SU(3) FHM upon doping.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283956","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}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054214
Álvaro Corral, Mónica Minjares, Marcelo Barreiro
The Madden-Julian oscillation (MJO) is a tropical weather system that has an important influence in the tropics and beyond; however, many of its characteristics are poorly understood, including their initiation and termination. Here we define Madden-Julian events as contiguous time periods with an active MJO, and we show that both the durations and the sizes of these events are well described by a double power-law distribution. Thus, small events have no characteristic scale, and the same for large events; nevertheless, both types of events are separated by a characteristic duration of about 27 days (this corresponds to half a cycle, roughly). Thus, after 27 days, there is a sharp increase in the probability that an event becomes extinct. We find that this effect is independent of the starting and ending phases of the events, which seems to point to an internal mechanism of exhaustion rather than to the effect of an external barrier. Our results would imply an important limitation of the MJO as a driver of subseasonal predictability.
{"title":"Increased extinction probability of the Madden-Julian oscillation after about 27 days","authors":"Álvaro Corral, Mónica Minjares, Marcelo Barreiro","doi":"10.1103/physreve.108.054214","DOIUrl":"https://doi.org/10.1103/physreve.108.054214","url":null,"abstract":"The Madden-Julian oscillation (MJO) is a tropical weather system that has an important influence in the tropics and beyond; however, many of its characteristics are poorly understood, including their initiation and termination. Here we define Madden-Julian events as contiguous time periods with an active MJO, and we show that both the durations and the sizes of these events are well described by a double power-law distribution. Thus, small events have no characteristic scale, and the same for large events; nevertheless, both types of events are separated by a characteristic duration of about 27 days (this corresponds to half a cycle, roughly). Thus, after 27 days, there is a sharp increase in the probability that an event becomes extinct. We find that this effect is independent of the starting and ending phases of the events, which seems to point to an internal mechanism of exhaustion rather than to the effect of an external barrier. Our results would imply an important limitation of the MJO as a driver of subseasonal predictability.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283961","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}
Pub Date : 2023-11-13DOI: 10.1103/physrevb.108.184104
Saransh Singh, Richard Briggs, Martin G. Gorman, Lorin X. Benedict, Christine J. Wu, Sebastien Hamel, Amy L. Coleman, Federica Coppari, Amalia Fernandez-Pañella, Christopher McGuire, Melissa Sims, June K. Wicks, Jon H. Eggert, Dayne E. Fratanduono, Raymond F. Smith
We combine nanosecond laser shock compression with in situ picosecond x-ray diffraction to provide structural data on iron up to 275 GPa. We constrain the extent of hcp-liquid coexistence, the onset of total melt, and the structure within the liquid phase. Our results indicate that iron, under shock compression, melts completely by 258(8) GPa. A coordination number analysis indicates that iron is a simple liquid at these pressure-temperature conditions. We also perform texture analysis between the ambient body-centered-cubic (bcc) $ensuremath{alpha}$, and the hexagonal-closed-packed (hcp) high-pressure $ensuremath{epsilon}ensuremath{-}mathrm{phase}$. We rule out the Rong-Dunlop orientation relationship (OR) between the $ensuremath{alpha}$ and $ensuremath{epsilon}ensuremath{-}mathrm{phase}mathrm{s}$. However, we cannot distinguish between three other closely related ORs: Burger's, Mao-Bassett-Takahashi, and Potter's OR. The solid-liquid coexistence region is constrained from a melt onset pressure of 225(3) GPa from previously published sound speed measurements and full melt [246.5(1.8)--258(8) GPa] from x-ray diffraction measurements, with an associated maximum latent heat of melting of 623 J/g. This value is lower than recently reported theoretical estimates and suggests that the contribution to the earth's geodynamo energy budget from heat release due to freezing of the inner core is smaller than previously thought. Melt pressures for these nanosecond shock experiments are consistent with gas gun shock experiments that last for microseconds, indicating that the melt transition occurs rapidly.
{"title":"Structural study of hcp and liquid iron under shock compression up to 275 GPa","authors":"Saransh Singh, Richard Briggs, Martin G. Gorman, Lorin X. Benedict, Christine J. Wu, Sebastien Hamel, Amy L. Coleman, Federica Coppari, Amalia Fernandez-Pañella, Christopher McGuire, Melissa Sims, June K. Wicks, Jon H. Eggert, Dayne E. Fratanduono, Raymond F. Smith","doi":"10.1103/physrevb.108.184104","DOIUrl":"https://doi.org/10.1103/physrevb.108.184104","url":null,"abstract":"We combine nanosecond laser shock compression with in situ picosecond x-ray diffraction to provide structural data on iron up to 275 GPa. We constrain the extent of hcp-liquid coexistence, the onset of total melt, and the structure within the liquid phase. Our results indicate that iron, under shock compression, melts completely by 258(8) GPa. A coordination number analysis indicates that iron is a simple liquid at these pressure-temperature conditions. We also perform texture analysis between the ambient body-centered-cubic (bcc) $ensuremath{alpha}$, and the hexagonal-closed-packed (hcp) high-pressure $ensuremath{epsilon}ensuremath{-}mathrm{phase}$. We rule out the Rong-Dunlop orientation relationship (OR) between the $ensuremath{alpha}$ and $ensuremath{epsilon}ensuremath{-}mathrm{phase}mathrm{s}$. However, we cannot distinguish between three other closely related ORs: Burger's, Mao-Bassett-Takahashi, and Potter's OR. The solid-liquid coexistence region is constrained from a melt onset pressure of 225(3) GPa from previously published sound speed measurements and full melt [246.5(1.8)--258(8) GPa] from x-ray diffraction measurements, with an associated maximum latent heat of melting of 623 J/g. This value is lower than recently reported theoretical estimates and suggests that the contribution to the earth's geodynamo energy budget from heat release due to freezing of the inner core is smaller than previously thought. Melt pressures for these nanosecond shock experiments are consistent with gas gun shock experiments that last for microseconds, indicating that the melt transition occurs rapidly.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283964","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}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054213
M. Vijayajayanthi, T. Kanna, M. Lakshmanan
The universal optical logic gates, namely, nand and nor gates, have been theoretically simulated by employing the energy sharing collision of bright optical solitons in the Manakov system, governing pulse propagation in a highly birefringent fiber. Further, we also realize the two-input optical logic gates, such as and, or, xor, xnor, for completeness of our scheme. Interestingly, our idea behind the simulation naturally satisfies all the criteria for practical optical logic, which in turn displays the strength and versatility of our theoretical simulation of universal optical logic gates. Hence, our approach paves the way for the experimentalists to create a new avenue in this direction if the energy sharing collisions of Manakov solitons are experimentally realized in the future.
{"title":"Simulation of universal optical logic gates under energy sharing collisions of Manakov solitons and fulfillment of practical optical logic criteria","authors":"M. Vijayajayanthi, T. Kanna, M. Lakshmanan","doi":"10.1103/physreve.108.054213","DOIUrl":"https://doi.org/10.1103/physreve.108.054213","url":null,"abstract":"The universal optical logic gates, namely, nand and nor gates, have been theoretically simulated by employing the energy sharing collision of bright optical solitons in the Manakov system, governing pulse propagation in a highly birefringent fiber. Further, we also realize the two-input optical logic gates, such as and, or, xor, xnor, for completeness of our scheme. Interestingly, our idea behind the simulation naturally satisfies all the criteria for practical optical logic, which in turn displays the strength and versatility of our theoretical simulation of universal optical logic gates. Hence, our approach paves the way for the experimentalists to create a new avenue in this direction if the energy sharing collisions of Manakov solitons are experimentally realized in the future.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136282893","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}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.055304
Gunnar Thorgilsson, Sigurdur I. Erlingsson
In quantum transport calculations, the proper handling of incoming and outgoing modes for retarded Green's functions is achieved via the lead self-energies. Computationally efficient and accurate methods to calculate the self-energies are thus very important. Here we present an alternative method for calculating lead self-energies which improves on a standard approach to solving quadratic eigenvalue problems that arise in quantum transport modeling. The method is based on a perturbative analysis of the generalized Schur decomposition to determine the relevant set of eigenvalues for transmitting modes. This allows us to circumvent finding the velocities of the modes (left- or right-moving) that are needed in order to calculate the lead Green's function from translationally invariant Green's functions. This saves computational time irrespective of the value of the imaginary part added to the energy. We compare our method with two existing methods---a popular iterative method and a standard eigenvalue method that explicitly calculates the velocities of the propagating modes. Our comparison shows that both eigenvalue methods are more robust than the iterative method. Furthermore, the comparison also shows that above a small threshold of propagating modes, the standard eigenvalue method requires extra computation time over our perturbation method. This excess of computation time grows linearly with the number of propagating modes.
{"title":"Lead Green's functions from quadratic eigenvalue problems without mode velocity calculations","authors":"Gunnar Thorgilsson, Sigurdur I. Erlingsson","doi":"10.1103/physreve.108.055304","DOIUrl":"https://doi.org/10.1103/physreve.108.055304","url":null,"abstract":"In quantum transport calculations, the proper handling of incoming and outgoing modes for retarded Green's functions is achieved via the lead self-energies. Computationally efficient and accurate methods to calculate the self-energies are thus very important. Here we present an alternative method for calculating lead self-energies which improves on a standard approach to solving quadratic eigenvalue problems that arise in quantum transport modeling. The method is based on a perturbative analysis of the generalized Schur decomposition to determine the relevant set of eigenvalues for transmitting modes. This allows us to circumvent finding the velocities of the modes (left- or right-moving) that are needed in order to calculate the lead Green's function from translationally invariant Green's functions. This saves computational time irrespective of the value of the imaginary part added to the energy. We compare our method with two existing methods---a popular iterative method and a standard eigenvalue method that explicitly calculates the velocities of the propagating modes. Our comparison shows that both eigenvalue methods are more robust than the iterative method. Furthermore, the comparison also shows that above a small threshold of propagating modes, the standard eigenvalue method requires extra computation time over our perturbation method. This excess of computation time grows linearly with the number of propagating modes.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283304","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}
Pub Date : 2023-11-13DOI: 10.1103/physrevb.108.l201110
Feng Chen, D. N. Sheng
Recent experimental progress has established the twisted bilayer transition metal dichalcogenide (TMD) as a highly tunable platform for studying many-body physics. Particularly, the homobilayer TMDs under displacement field are believed to be described by a generalized triangular-lattice Hubbard model with a spin-dependent hopping phase $ensuremath{theta}$. To explore the effects of $ensuremath{theta}$ on the system, we perform density matrix renormalization group calculations for the relevant triangular lattice t-J model. By changing $ensuremath{theta}$ at small hole doping, we obtain a region of quasi-long-range superconducting order coexisting with charge and spin density wave within $0
{"title":"Singlet, triplet, and pair density wave superconductivity in the doped triangular-lattice moiré system","authors":"Feng Chen, D. N. Sheng","doi":"10.1103/physrevb.108.l201110","DOIUrl":"https://doi.org/10.1103/physrevb.108.l201110","url":null,"abstract":"Recent experimental progress has established the twisted bilayer transition metal dichalcogenide (TMD) as a highly tunable platform for studying many-body physics. Particularly, the homobilayer TMDs under displacement field are believed to be described by a generalized triangular-lattice Hubbard model with a spin-dependent hopping phase $ensuremath{theta}$. To explore the effects of $ensuremath{theta}$ on the system, we perform density matrix renormalization group calculations for the relevant triangular lattice t-J model. By changing $ensuremath{theta}$ at small hole doping, we obtain a region of quasi-long-range superconducting order coexisting with charge and spin density wave within $0<ensuremath{theta}<ensuremath{pi}/3$. The superconductivity is composed of a dominant spin singlet $d$-wave and a subdominant triplet $p$-wave pairing. Intriguingly, the ${S}_{z}=ifmmodepmelsetextpmfi{}1$ triplet pairing components feature pair-density waves. In addition, we find a region of triplet superconductivity coexisting with charge-density wave and ferromagnetism within $ensuremath{pi}/3<ensuremath{theta}<2ensuremath{pi}/3$, which is related to the former phase at smaller $ensuremath{theta}$ by a combined operation of spin-flip and gauge transformation. Our findings provide insights and directions for experimental search for exotic superconductivity in twisted TMD systems.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283805","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}
Pub Date : 2023-11-13DOI: 10.1103/physreva.108.052412
J. M. Gomez Llorente, I. Gomez-Ojeda, J. Plata
We analyze the robust character against the nonstatic noise of clock transitions implemented via a method of continuous dynamical decoupling (CDD) in a hyperfine Zeeman multiplet in $^{87}mathrm{Rb}$. The emergence of features specific to the quadratic corrections to the linear Zeeman effect is evaluated. Our analytical approach, which combines methods of stochastic analysis with time-dependent perturbation theory, allows tracing the deco- herence process for generic noise sources. Working first with a basic CDD scheme, it is shown that the amplitude and frequency of the (sinusoidal driving) field of control can be appropriately chosen to force the nonstatic random input to have a (time-dependent) perturbative character. Moreover, in the dressed-state picture, the effect of noise is described in terms of an operative random variable whose properties, dependent on the driving field, can be analytically characterized. In this framework, the relevance of the spectral density of the fluctuations to the performance of the CDD technique is precisely assessed. In particular, the range of noise correlation times where the method of decoherence reduction is still efficient is identified. The results obtained in the basic CDD framework are extrapolated to concatenated schemes. The generality of our approach allows its applicability beyond the specific atomic system considered.
{"title":"Decoherence reduction via continuous dynamical decoupling: Analytical study of the role of the noise spectrum","authors":"J. M. Gomez Llorente, I. Gomez-Ojeda, J. Plata","doi":"10.1103/physreva.108.052412","DOIUrl":"https://doi.org/10.1103/physreva.108.052412","url":null,"abstract":"We analyze the robust character against the nonstatic noise of clock transitions implemented via a method of continuous dynamical decoupling (CDD) in a hyperfine Zeeman multiplet in $^{87}mathrm{Rb}$. The emergence of features specific to the quadratic corrections to the linear Zeeman effect is evaluated. Our analytical approach, which combines methods of stochastic analysis with time-dependent perturbation theory, allows tracing the deco- herence process for generic noise sources. Working first with a basic CDD scheme, it is shown that the amplitude and frequency of the (sinusoidal driving) field of control can be appropriately chosen to force the nonstatic random input to have a (time-dependent) perturbative character. Moreover, in the dressed-state picture, the effect of noise is described in terms of an operative random variable whose properties, dependent on the driving field, can be analytically characterized. In this framework, the relevance of the spectral density of the fluctuations to the performance of the CDD technique is precisely assessed. In particular, the range of noise correlation times where the method of decoherence reduction is still efficient is identified. The results obtained in the basic CDD framework are extrapolated to concatenated schemes. The generality of our approach allows its applicability beyond the specific atomic system considered.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283823","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}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.l053202
Z. M. Raspopović
A pulse of noninteracting charged particles in an unbounded gas, exposed to a low, constant, homogeneous electric field, was studied in both space and time using a Monte Carlo simulation technique. The difference in electrical potential between the leading and trailing edges of the swarm results in the space-resolved average ion kinetic energy becoming a linearly increasing function of space. This Letter analyzes whether the average ion kinetic energy at the leading edge reaches a stationary value during the spatiotemporal evolution of the swarm, as has been considered so far. When the swarm's mean kinetic energy reaches a steady-state value, indicating that an energy balance is established over time, the gains (from the field) and losses (due to collisions) are nonuniform across space. The local power balance is negative at the front of the swarm and positive at the tail. Cooling the ions at the front and heating the ions at the tail results in a decrease in the average ion kinetic energy at the front and an increase at the tail. Thus, it can be concluded that stationary values of average ion kinetic energy do not exist at the leading and trailing edges during the evolution. Instead, they tend to approach the swarm's mean kinetic energy as $tensuremath{rightarrow}ensuremath{infty}$.
{"title":"Space-resolved average kinetic energy of ion swarms in a uniform electric field","authors":"Z. M. Raspopović","doi":"10.1103/physreve.108.l053202","DOIUrl":"https://doi.org/10.1103/physreve.108.l053202","url":null,"abstract":"A pulse of noninteracting charged particles in an unbounded gas, exposed to a low, constant, homogeneous electric field, was studied in both space and time using a Monte Carlo simulation technique. The difference in electrical potential between the leading and trailing edges of the swarm results in the space-resolved average ion kinetic energy becoming a linearly increasing function of space. This Letter analyzes whether the average ion kinetic energy at the leading edge reaches a stationary value during the spatiotemporal evolution of the swarm, as has been considered so far. When the swarm's mean kinetic energy reaches a steady-state value, indicating that an energy balance is established over time, the gains (from the field) and losses (due to collisions) are nonuniform across space. The local power balance is negative at the front of the swarm and positive at the tail. Cooling the ions at the front and heating the ions at the tail results in a decrease in the average ion kinetic energy at the front and an increase at the tail. Thus, it can be concluded that stationary values of average ion kinetic energy do not exist at the leading and trailing edges during the evolution. Instead, they tend to approach the swarm's mean kinetic energy as $tensuremath{rightarrow}ensuremath{infty}$.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283975","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}
Pub Date : 2023-11-13DOI: 10.1103/physreva.108.052811
Johan Hörnquist, Patrik Hedvall, Ann E. Orel, Åsa Larson
Associative ionization in collisions of ${mathrm{H}}^{+}+{mathrm{H}}^{ensuremath{-}}$ as well as $mathrm{H}(1s)+mathrm{H}(ns)$ with $n=2,3,4$ is studied theoretically. Relevant adiabatic potential curves and nonadiabatic couplings are calculated ab initio and the autoionization from the lowest electronic resonant states in the ${}^{1}{mathrm{ensuremath{Sigma}}}_{g/u}^{+}$ and ${}^{3}{mathrm{ensuremath{Sigma}}}_{g/u}^{+}$ symmetries are considered. The cross sections are obtained by solving the coupled Schr"odinger equation, including a complex potential matrix, in a strict diabatic representation. The importance of using a nonlocal description of autoionization is investigated. Associative ionization is also studied for different isotopes of hydrogen. Calculated cross sections are compared with results from measurements.
{"title":"Associative ionization in collisions of H++H− and H(1<mml:mi…","authors":"Johan Hörnquist, Patrik Hedvall, Ann E. Orel, Åsa Larson","doi":"10.1103/physreva.108.052811","DOIUrl":"https://doi.org/10.1103/physreva.108.052811","url":null,"abstract":"Associative ionization in collisions of ${mathrm{H}}^{+}+{mathrm{H}}^{ensuremath{-}}$ as well as $mathrm{H}(1s)+mathrm{H}(ns)$ with $n=2,3,4$ is studied theoretically. Relevant adiabatic potential curves and nonadiabatic couplings are calculated ab initio and the autoionization from the lowest electronic resonant states in the ${}^{1}{mathrm{ensuremath{Sigma}}}_{g/u}^{+}$ and ${}^{3}{mathrm{ensuremath{Sigma}}}_{g/u}^{+}$ symmetries are considered. The cross sections are obtained by solving the coupled Schr\"odinger equation, including a complex potential matrix, in a strict diabatic representation. The importance of using a nonlocal description of autoionization is investigated. Associative ionization is also studied for different isotopes of hydrogen. Calculated cross sections are compared with results from measurements.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136282706","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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