Article
Physics, Multidisciplinary
Milosz Panfil, Sarang Gopalakrishnan, Robert M. Konik
Summary: Many experimentally relevant systems are quasi-one-dimensional, consisting of nearly decoupled chains, where weak interchain couplings play a crucial role in thermalizing the system. We developed a Boltzmann-equation formalism involving a collision integral that is asymptotically exact for any interacting integrable system, and applied it to study relaxation in coupled Bose gases in the Newton's cradle setup. We found that relaxation involves a broad spectrum of timescales and the Markov process governing relaxation at late times is gapless, leading to nonexponential approach to equilibrium even for spatially uniform perturbations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
A. Alnor, T. Baekkegaard, N. T. Zinner
Summary: Different topological phases of quantum systems have been a focus of research in recent decades. This study goes beyond typical spin-1/2 systems and explores the realization of higher Chern numbers and the emergence of different topological phases using spin-1 systems. The results show that rich topological phase diagrams can be achieved through numerical and analytical methods, and the realistic implementation of spin-1 systems in superconducting circuits holds promise for experimental verification of these theoretical predictions.
Article
Multidisciplinary Sciences
George Gillard, Edmund Clarke, Evgeny A. Chekhovich
Summary: This study demonstrates millisecond coherence times for a nuclear spin ensemble coupled to a single electron spin qubit in a semiconductor quantum dot, providing new understanding of the many-body coherence in central spin systems required for the development of electron-nuclear spin qubits.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Tomotaka Kuwahara, Keiji Saito
Summary: This work investigates the propagation of local perturbations in interacting boson systems with Bose-Hubbard Hamiltonians. The study proves the existence of an almost-linear information-propagation light cone and establishes a Lieb-Robinson bound. Additionally, the research explores the clustering theorem for gapped ground states and the time complexity of simulating one-dimensional quench dynamics.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Andrea Pizzi, Johannes Knolle, Andreas Nunnenkamp
Summary: Researchers have found that in the presence of long-range interactions and transverse fields, a clean spin-1/2 system can support a variety of different 'higher-order' discrete time crystals with integer and even fractional values of n. These phases, characterized as arguably prethermal non-equilibrium states, are stable in models with continuous driving and time-independent interactions, making them suitable for experimental implementations using ultracold atoms or trapped ions.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Savannah Garmon, Gonzalo Ordonez, Naomichi Hatano
Summary: This research demonstrates how a characteristic triple-level convergence occurs when a quantum emitter is coupled near threshold to a one-dimensional continuum with a van Hove singularity in the density of states. As the coupling is shut off, only two discrete states coalesce into a 2 x 2 Jordan block while the third state merges with the continuum. The quantum emitter decay shows an unusual form 1 - Ct(3/2) on the key timescale.
PHYSICAL REVIEW RESEARCH
(2021)
Review
Chemistry, Multidisciplinary
Ivan Marri, Stefano Ossicini
Summary: The development of novel nanostructured solar cell devices using low-dimensional materials has shown potential in improving energy conversion efficiency. Utilizing quantum confinement effects in nanocrystals and carrier multiplication technology are key strategies for enhancing the performance of photovoltaic systems.
Article
Physics, Fluids & Plasmas
A. Patron, B. Sanchez-Rey, A. Prados
Summary: The study analyzes the dynamical evolution of a fluid with nonlinear drag, described by the Enskog-Fokker-Planck equation. The model system displays a complex glassy response at low temperatures, controlled by a long-lived nonequilibrium state. The observed response includes nonexponential, algebraic, relaxation, and strong memory effects, presenting scaling properties.
Article
Physics, Multidisciplinary
Tomotaka Kuwahara, Keiji Saito
Summary: This study disproves fast scrambling in generic long-range interacting systems with alpha > D, where the OTOC shows a polynomial growth over time as long as alpha > D and the necessary scrambling time over a distance R is larger than t greater than or similar to R[(2 alpha-2D)/(2 alpha-D+1)].
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Chufan Lyu, Xiaoyu Tang, Junning Li, Xusheng Xu, Man-Hong Yung, Abolfazl Bayat
Summary: Current quantum simulators face limitations in coherence time, operations quality, readout accuracy, and qubit connectivity. Variational quantum algorithms are the most promising approach for near-term practical quantum advantage. This study explores variational quantum algorithms with different qubit connectivity levels for digital simulation of long-range interacting systems and generation of spin squeezed states. The results show that longer-range interactions decrease the efficiency and fidelity of the algorithms, requiring more optimization iterations. Increasing qubit connectivity improves results with fewer resources. Mixing circuit layers with different connectivity levels can significantly enhance performance. The same circuit design can also be used for variational spin squeezed state generation for quantum metrology.
NEW JOURNAL OF PHYSICS
(2023)
Article
Optics
Hugo Molinares, Vitalie Eremeev, Miguel Orszag
Summary: In a hybrid scheme involving a three-level atom-cavity-oscillator system, the synchronization and transfer of nonclassical states between the mechanical oscillator and the cavity field are demonstrated. The results show the feasibility of synchronizing and transferring quantum states with high fidelity under specific initial conditions.
Article
Materials Science, Multidisciplinary
Alan Morningstar, Nicholas O'Dea, Jonas Richter
Summary: In systems with conserved density, the additional conservation of the center of mass has been found to slow down hydrodynamics. However, long-range interactions generally result in faster transport and information propagation. In this study, we investigate the competition between these two effects and develop a hydrodynamic theory for long-range center-of-mass-conserving systems, showing a rich dynamical phase diagram with varying dynamical exponents.
Article
Materials Science, Multidisciplinary
Tianci Zhou, Andrew Guo, Shenglong Xu, Xiao Chen, Brian Swingle
Summary: The FKPP equation provides a mean-field theory for out-of-time ordered commutators in quantum chaotic systems. The fractional-derivative FKPP equation offers a mean-field theory for systems with power-law interactions. However, the fractional FKPP description is subject to strong quantum fluctuation effects, and its effectiveness for generic chaotic systems with power-law interactions is unclear. This study investigates this problem using a model of coupled quantum dots and demonstrates that the parameters of the effective theory can be chosen to reproduce the previously found butterfly light cone scalings.
Article
Chemistry, Multidisciplinary
Jesus Valdiviezo, Paulina Rocha, Anastazia Polakovsky, Julio L. Palma
Summary: In the study, the conductance of acene derivatives connected to gold electrodes was calculated using density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) formalism. It was found that the systems exhibit near length-independent conductance and can show an increase with molecular length, depending on the connection to the electrodes. The analysis attributes this behavior to the decrease of the HOMO-LUMO gap with length, shifting the transmission peaks near the Fermi level.
Article
Physics, Multidisciplinary
S. M. Wang, W. Nazarewicz, A. Volya, Y. G. Ma
Summary: The most important law of radioactivity is the exponential decay law, which is, however, neither rigorous nor fundamental in the realm of quantum mechanics. While deviations from exponential decay have been observed experimentally at the early stage of decay, there is little evidence for nonexponential behavior at long times. Nonetheless, theoretically, long-term nonexponentiality is expected to reveal the nonresonant background components of the initial wave function and provide information about interference and memory. This paper proposes new observables for experimental investigations of the post-exponential decay regime, with examples in atomic nuclei, but applicable to other many-body open quantum systems.
PHYSICAL REVIEW RESEARCH
(2023)
News Item
Physics, Multidisciplinary
Lea F. Santos
Summary: A clever application of nuclear magnetic resonance techniques allows a glimpse into a quantum system being driven at high frequency, resulting in Floquet prethermalization - a quasi-steady state that persists for a very long time.
Article
Physics, Multidisciplinary
M. Carrera-Nunez, A. M. Martinez-Arguello, J. M. Torres, E. J. Torres-Herrera
Summary: This study investigates the time dynamics of random density matrices generated by evolving the same pure state using a Gaussian orthogonal ensemble (GOE) of Hamiltonians. It is shown that the resulting mixed state exhibits spectral statistics that can be well described by random matrix theory (RMT), undergoing a crossover from GOE to the Gaussian unitary ensemble (GUE) for short and large times, respectively. By employing a semi-analytical treatment based on a power series, the crossover is found to occur in a characteristic time that scales inversely with the Hilbert space dimension. The results from RMT are compared with a paradigmatic model of many-body localization in the chaotic regime, where GUE statistics is reached at large times, while the statistics for short times strongly depend on the specific subspace considered.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Multidisciplinary
David Villasenor, Saul Pilatowsky-Cameo, Miguel A. Bastarrachea-Magnani, Sergio Lerma-Hernandez, Lea F. Santos, Jorge G. Hirsch
Summary: We analyze the relationship between chaos and thermalization onset in the spin-boson Dicke model. The eigenstate expectation values and distributions of off-diagonal elements validate the eigenstate thermalization hypothesis (ETH) in the chaotic region, indicating thermalization. The chaotic structure of the eigenstates is confirmed using von Neumann entanglement entropy and Shannon entropy.
Article
Physics, Multidisciplinary
David A. Zarate-Herrada, Lea F. Santos, E. Jonathan Torres-Herrera
Summary: Survival probability is a measure of the likelihood that a system remains in its initial state after being taken out of equilibrium. Drawing on the concept of generalized entropies used to analyze nonergodic states, we propose a generalized version of the survival probability and explore its potential in studying eigenstate structure and ergodicity.
Article
Quantum Science & Technology
Jorge Chavez-Carlos, Talia L. M. Lezama, Rodrigo G. G. Cortinas, Jayameenakshi Venkatraman, Michel H. H. Devoret, Victor S. S. Batista, Francisco Perez-Bernal, Lea F. F. Santos
Summary: Transmon qubits are widely used in circuit-based quantum information processing due to their controllability and ease of engineering implementation. In addition to serving as qubits, transmons can also be used to investigate fundamental physics questions. This study explores their use as simulators of excited state quantum phase transitions (ESQPTs), and shows that experimentally observed spectral kissing in a driven SNAIL-transmon is a precursor to ESQPT. The study further explores the dynamical consequences of ESQPT, which have implications for superconducting circuits, cold atoms, and ion traps experiments.
NPJ QUANTUM INFORMATION
(2023)
Article
Materials Science, Multidisciplinary
Luis Benet, Fausto Borgonovi, Felix M. Izrailev, Lea F. Santos
Summary: We study the quantum-classical correspondence for strongly chaotic systems with interacting spin particles and fixed angular momenta. Through analyzing Lyapunov spectra, we find that the largest Lyapunov exponent agrees with the exponent determining the local instability of each individual spin. In the quantum domain, we analyze the Hamiltonian matrix to determine the conditions for quantum chaos based on the model parameters. By comparing the quantum and classical domains, we establish the relationship between quantum quantities and their classical counterparts, such as the local density of states and the chaotic eigenfunctions.
Article
Optics
A. L. M. Southier, Lea F. Santos, P. H. Souto Ribeiro, A. D. Ribeiro
Summary: This article presents an alternative approach to identify prime numbers based on the evolution of linear entanglement entropy. The authors demonstrate a connection between prime numbers and a singular behavior in the amplitudes of the Fourier series of this entropy. They also discuss the experimental implementation of this method using existing optical devices and explore a possible relationship between their results and the zeros of the Riemann zeta function.
Article
Materials Science, Multidisciplinary
Isaias Vallejo-Fabila, Jonathan Torres-Herrera
Summary: This study numerically investigates the effects of autocorrelated disorder on a one-dimensional many-body localized quantum system, and finds that strong correlations between on-site potentials suppress the many-body localized phase.
Article
Physics, Fluids & Plasmas
Wouter Buijsman, Talia L. M. Lezama, Tamar Leiser, Lea F. Santos
Summary: This article studies the applications of extreme-value distributions in various contexts, with a focus on the ground-state energy distribution of disordered many-body quantum systems. An analytical expression is derived that accurately describes the ground-state energy distribution of the systems, reproducing Tracy-Widom distribution for some models but showing discrepancies for others. The analytical expression captures all of these distributions, playing a similar role as the Brody distribution does for the bulk of the spectrum.
Article
Physics, Fluids & Plasmas
Karin Wittmann W, E. R. Castro, Angela Foerster, Lea F. Santos
Summary: The onset of quantum chaos in triple-well potential systems of interacting bosons is investigated. Even in its chaotic regime, the system exhibits features reminiscent of integrability.
Article
Quantum Science & Technology
Saul Pilatowsky-Cameo, David Villasenor, Miguel A. Bastarrachea-Magnani, Sergio Lerma-Hernandez, Lea F. Santos, Jorge G. Hirsch
Summary: This paper explores a method for quantifying the degree of localization of quantum states in phase space and introduces an effective measure for revealing quantum scars. By analyzing the high moments of the Husimi function, unstable periodic orbits in the model are identified qualitatively and quantitatively.
Article
Materials Science, Multidisciplinary
Yifei Liu, Lea F. Santos, Emil Prodan
Summary: This study investigates topological phases and their bulk-boundary principles supported by quasiperiodic spin-chain models using numerical and K-theoretic methods. It is shown that the operator algebras generating the Hamiltonians are noncommutative tori for both uncorrelated and correlated phases, resulting in physical properties similar to the quantum Hall effect in higher dimensions. The interaction strongly influences the robust topological edge modes, which exhibit hybrid edge-localized and chain-delocalized structures. The findings lay the groundwork for topological spin pumping using phason as an adiabatic parameter.
Article
Materials Science, Multidisciplinary
Talia L. M. Lezama, E. Jonathan Torres-Herrera, Francisco Perez-Bernal, Yevgeny Bar Lev, Lea F. Santos
Summary: The equilibration time of isolated many-body quantum systems far from equilibrium depends on system size and observables. If dynamical manifestations of spectral correlations are taken into account, the equilibration time scales exponentially with system size.
Article
Physics, Multidisciplinary
Andrei Solorzano, Lea F. Santos, E. Jonathan Torres-Herrera
Summary: Finite-size effects and lack of self-averaging are major concerns in studies of many-body localization. By considering a large number of samples for all system sizes, the generalized dimensions of eigenstates can be well described, providing an additional tool for research in this area.
PHYSICAL REVIEW RESEARCH
(2021)
