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The many-body state of carriers confined in a quantum dot is controlled by the balance between their kinetic energy and their Coulomb correlation. In coupled quantum dots, both can be tuned by varying the inter-dot tunneling and…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Massimo Rontani , Filippo Troiani , Ulrich Hohenester , Elisa Molinari

We use the numerical renormalization group method to investigate the spectral properties of a single-impurity Anderson model with a gap {\delta} across the Fermi level in the conduction-electron spectrum. For any finite {\delta} > 0, at…

Mesoscale and Nanoscale Physics · Physics 2010-06-22 Catalin Pascu Moca , Adrian Roman

We study a pseudogap Anderson-Holstein model of a magnetic impurity level that hybridizes with a conduction band whose density of states vanishes in power-law fashion at the Fermi energy, and couples, via its charge, to a nondispersive…

Strongly Correlated Electrons · Physics 2013-02-27 Mengxing Cheng , Kevin Ingersent

The entanglement entropy and quantum fidelity in a hard-core-boson model with nearest- and next-nearest-neighbor interactions are studied numerically. By using exact diagonalization and the density matrix renormalization group, the effects…

Strongly Correlated Electrons · Physics 2012-12-18 Jie Ren , Xuefen Xu , Liping Gu , Jialiang Li

The sensitivity of quantum systems to external disturbances is a fundamental problem for the implementation of functional quantum devices, quantum information and computation. Based on remarkable experimental progress in optics and…

Quantum Physics · Physics 2021-04-21 A. R. C. Buarque , W. S. Dias

Phase transitions have recently been formulated in the time domain of quantum many-body systems, a phenomenon dubbed dynamical quantum phase transitions (DQPTs), whose phenomenology is often divided in two types. One refers to distinct…

Quantum Physics · Physics 2021-01-04 Ricardo Puebla

We demonstrate that the multiplicity distribution of a system located in the vicinity of a first-order phase transition can be successfully measured in terms of its factorial cumulants with a surprisingly small number of events. This…

Nuclear Theory · Physics 2019-11-20 Adam Bzdak , Volker Koch

Quantum measurements and phase transitions are seemingly uncorrelated topics, but here we show that phase transitions occur in sequential quantum measurements. We find that the probability distribution of the measurement results of a…

Quantum Physics · Physics 2018-07-17 Wen-Long Ma , Ping Wang , Weng-Hang Leong , Ren-Bao Liu

We examine the complexity of learning the distributions produced by finite-state quantum sources. We show how prior techniques for learning hidden Markov models can be adapted to the quantum generator model to find that the analogous state…

Quantum Physics · Physics 2009-10-21 Brendan Juba

Quantum phase transitions occur when the ground state of a quantum system undergoes a qualitative change when an external control parameter reaches a critical value. Here, we demonstrate a technique for studying quantum systems undergoing a…

Quantum Physics · Physics 2008-03-14 Jingfu Zhang , Xinhua Peng , Nageswaran Rajendran , Dieter Suter

The quantum phase transitions provide a paradigm for studying collective quantum phenomena that are a result of competing non-commuting interactions. This paper will study the ground state properties and quantum critical dynamics of the…

Quantum Physics · Physics 2026-01-27 Rudraksh Sharma

Quantum computers promise to perform computations beyond the reach of modern computers with profound implications for scientific research. Due to remarkable technological advances, small scale devices are now becoming available for use. One…

Strongly Correlated Electrons · Physics 2022-05-20 Adam Smith , Bernhard Jobst , Andrew G. Green , Frank Pollmann

Quantum phase transitions are highly remarkable phenomena manifesting in quantum many-body systems. However, their precise identifications in equilibrium systems pose significant theoretical and experimental challenges. Thus far, dynamical…

Quantum Physics · Physics 2025-05-16 Kaito Kobayashi , Yukitoshi Motome

We present the first computationally-efficient algorithm for average-case learning of shallow quantum circuits with many-qubit gates. Specifically, we provide a quasi-polynomial time and sample complexity algorithm for learning unknown…

Quantum Physics · Physics 2025-06-11 Francisca Vasconcelos , Hsin-Yuan Huang

Collective phenomena in the Tavis-Cummings model has been widely studied, focusing on the phase transition features. In many occasions, it has been used variational approaches that consider separated radiation-matters systems. In this…

Quantum Physics · Physics 2021-01-19 J. P. Restrepo Cuartas , H. Vinck-Posada

Quantum computational supremacy arguments, which describe a way for a quantum computer to perform a task that cannot also be done by a classical computer, typically require some sort of computational assumption related to the limitations of…

Quantum Physics · Physics 2020-05-13 Alexander M. Dalzell , Aram W. Harrow , Dax Enshan Koh , Rolando L. La Placa

The fundamental question of how to best simulate quantum systems using conventional computational resources lies at the forefront of condensed matter and quantum computation. It impacts both our understanding of quantum materials and our…

Strongly Correlated Electrons · Physics 2021-09-29 Juan Carrasquilla , Di Luo , Felipe Pérez , Ashley Milsted , Bryan K. Clark , Maksims Volkovs , Leandro Aolita

The concept of quantum phase transitions (QPT) plays a central role in the description of condensed matter systems. In this contribution, we perform high-quality wavefunction-based simulations to demonstrate the existence of a quantum phase…

Quantum Physics · Physics 2023-01-25 Tobias Serwatka , Roger G. Melko , Anton Burkov , Pierre-Nicholas Roy

Quantum machine learning offers a promising advantage in extracting information about quantum states, e.g. phase diagram. However, access to training labels is a major bottleneck for any supervised approach, preventing getting insights…

Quantum Physics · Physics 2023-02-13 Saverio Monaco , Oriel Kiss , Antonio Mandarino , Sofia Vallecorsa , Michele Grossi

Quantum phase transition in the one-dimensional period-two and uniform quantum compass model are studied by using the pseudo-spin transformation method and the trace map method. The exact solutions are presented, the fidelity, the…

Strongly Correlated Electrons · Physics 2009-11-13 Ke-Wei Sun , Yu-Yu Zhang , Qing-Hu Chen