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Related papers: Bures metric over thermal state manifolds and quan…

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We face the problem of detecting and featuring footprints of quantum criticality in the finite-temperature behavior of quantum many-body systems. Our strategy is that of comparing the phase diagram of a system displaying a T=0 quantum phase…

Statistical Mechanics · Physics 2007-08-09 Alessandro Cuccoli , Alessio Taiti , Ruggero Vaia , Paola Verrucchi

An explicit parameterization for the state space of an $n$-level density matrix is given. The parameterization is based on the canonical coset decomposition of unitary matrices. We also compute, explicitly, the Bures metric tensor over the…

Quantum Physics · Physics 2007-05-23 S. Javad Akhtarshenas

As the temperature of a many-body system approaches absolute zero, thermal fluctuations of observables cease and quantum fluctuations dominate. Competition between different energies, such as kinetic energy, interactions or thermodynamic…

Quantum Gases · Physics 2012-03-05 Xibo Zhang , Chen-Lung Hung , Shih-Kuang Tung , Cheng Chin

I review a variety of model systems and their quantum critical points, motivated by recent experimental and theoretical developments. These are used to present a general discussion of the non-zero temperature crossovers in the vicinity of a…

Strongly Correlated Electrons · Physics 2015-05-14 Subir Sachdev

In this article, we provide theoretical support for the use of geometric measures of nonclassicality as a general tool to identify quantum phase transitions. We argue that divergences in the susceptibility of any geometric measure of…

Quantum Physics · Physics 2020-09-02 Kok Chuan Tan

Interacting quantum systems illustrate complex phenomena including phase transitions to novel ordered phases. The universal nature of critical phenomena reduces their description to determining only the transition temperature and the…

We consider the scaling behavior of thermodynamic quantities in the one-dimensional transverse-field Ising model near its quantum critical point (QCP). Our study has been motivated by the question about the thermodynamical signatures of…

Strongly Correlated Electrons · Physics 2018-06-20 Jianda Wu , Lijun Zhu , Qimiao Si

Dimensionality is a fundamental concept in physics, which plays a hidden but crucial role in various domains, including condensed matter physics, relativity and string theory, statistical physics, etc. In quantum physics, reducing…

Berry phases and the quantum-information theoretic notion of fidelity have been recently used to analyze quantum phase transitions from a geometrical perspective. In this paper we unify these two approaches showing that the underlying…

Quantum Physics · Physics 2007-12-10 Lorenzo Campos Venuti , Paolo Zanardi

A systematic method for the computation of finite temperature ($T$) crossover functions near quantum critical points close to, or above, their upper-critical dimension is devised. We describe the physics of the various regions in the $T$…

Condensed Matter · Physics 2008-12-18 Subir Sachdev

Quantum metrology fundamentally relies upon the efficient management of quantum uncertainties. We show that, under equilibrium conditions, the management of quantum noise becomes extremely flexible around the quantum critical point of a…

Quantum Physics · Physics 2018-07-18 Irénée Frérot , Tommaso Roscilde

The zero-temperature limit of a continuous phase transition is marked by a quantum critical point, which can generate exotic physics that extends to elevated temperatures. Magnetic quantum criticality is now well known, and has been…

Materials Science · Physics 2019-02-21 Awadhesh Narayan , Andres Cano , Alexander V. Balatsky , Nicola A. Spaldin

We study the identification of quantum phases of matter, at zero temperature, when only part of the phase diagram is known in advance. Following a supervised learning approach, we show how to use our previous knowledge to construct an…

Quantum Physics · Physics 2024-09-10 Mehran Khosrojerdi , Jason L. Pereira , Alessandro Cuccoli , Leonardo Banchi

Quantum sensing is one of the arenas that exemplifies the superiority of quantum technologies over their classical counterparts. Such superiority, however, can be diminished due to unavoidable noise and decoherence of the probe. Thus,…

Quantum Physics · Physics 2023-10-25 V. Montenegro , M. G. Genoni , A. Bayat , M. G. A. Paris

By setting the inverse temperature $\beta$ loose to occupy the complex plane, Fisher showed that the zeros of the complex partition function $Z$, if approaching the real $\beta$ axis, reveal a thermodynamic phase transition. More recently,…

Strongly Correlated Electrons · Physics 2025-01-17 Yang Liu , Songtai Lv , Yuchen Meng , Zefan Tan , Erhai Zhao , Haiyuan Zou

We apply the fidelity metric approach to analyze two recently introduced models that exhibit a quantum phase transition to a topologically ordered phase. These quantum models have a known connection to classical statistical mechanical…

Quantum Physics · Physics 2008-07-03 Damian F. Abasto , Alioscia Hamma , Paolo Zanardi

We study the linear conductance through a double-quantum-dot system consisting of an interacting dot in its Kondo regime and an effectively noninteracting dot, connected in parallel to metallic leads. Signatures in the zero-bias conductance…

Mesoscale and Nanoscale Physics · Physics 2008-10-13 Luis G. Dias da Silva , Kevin Ingersent , Nancy Sandler , Sergio Ulloa

Quantum phase transitions are a fascinating area of condensed matter physics. The extension through complexification not only broadens the scope of this field but also offers a new framework for understanding criticality and its statistical…

Strongly Correlated Electrons · Physics 2025-01-17 Yang Liu , Erhai Zhao , Haiyuan Zou

We review the non-zero temperature relaxational dynamics of quantum systems near a zero temperature, second-order phase transition. We begin with the quantum Ising chain, for which universal and exact results for the relaxation rates can be…

Strongly Correlated Electrons · Physics 2017-08-23 Subir Sachdev

Critical phenomena at finite temperature underpin a broad range of physical systems, yet their study remains challenging due to computational bottlenecks near phase transitions. Quantum annealers have attracted significant interest as a…

Statistical Mechanics · Physics 2025-07-11 Gianluca Teza , Francesco Campaioli , Marco Avesani , Oren Raz