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We study an effective theory for QCD at finite temperature and density which contains the leading center symmetric and center symmetry breaking terms. The effective theory is studied in a flux representation where the complex phase problem…

High Energy Physics - Lattice · Physics 2011-07-21 Ydalia Delgado Mercado , Hans Gerd Evertz , Christof Gattringer

A proposed paradigm for out-of-equilibrium quantum systems is that an analogue of quantum phase transitions exists between parameter regimes of qualitatively distinct time-dependent behavior. Here, we present evidence of such a transition…

Employing the self-learning quantum Monte Carlo algorithm, we investigate the frustrated transverse-field triangle-lattice Ising model coupled to a Fermi surface. Without fermions, the spin degrees of freedom undergoes a second-order…

Strongly Correlated Electrons · Physics 2018-07-17 Zi Hong Liu , Xiao Yan Xu , Yang Qi , Kai Sun , Zi Yang Meng

Quantum phase estimation is at the heart of most quantum algorithms with exponential speedup. In this letter we demonstrate how to utilize it to compute the dynamical response functions of many-body quantum systems. Specifically, we design…

Quantum Physics · Physics 2021-05-21 Dries Sels , Eugene Demler

Demonstrations of quantum computational advantage and benchmarks of quantum processors via quantum random circuit sampling are based on evaluating the linear cross-entropy benchmark (XEB). A key question in the theory of XEB is whether it…

We analyze the quantum process tomography (QPT) in the presence of decoherence, focusing on distinguishing local and non-local decoherence mechanisms for a two-partite system from experimental QPT data. In particular, we consider the…

Quantum Physics · Physics 2015-05-13 A. G. Kofman , A. N. Korotkov

This article surveys quantum computational complexity, with a focus on three fundamental notions: polynomial-time quantum computations, the efficient verification of quantum proofs, and quantum interactive proof systems. Properties of…

Quantum Physics · Physics 2008-04-23 John Watrous

The comprehension of quantum phase transitions (QPTs) is considered as a critical foothold in the field of many-body physics. Developing protocols to effectively identify and understand QPTs thus represents a key but challenging task for…

Quantum Physics · Physics 2025-04-03 Xiangbei Li , Yaoming Chu , Shaoliang Zhang , Jianming Cai

An investigation of the quantum phase transition in both discrete and continuum field Dicke models is presented. A series of anticrossing features following the criticality is revealed in the band of the field modes. Critical exponents are…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Denis Tolkunov , Dmitry Solenov

We construct a quantum Wajnflasz-Pick model that is a generalized quantum Ising model, and investigate a nature of quantum phase transitions of the model with infinite-range interactions. Quantum phase transition phenomena have drawn…

Statistical Mechanics · Physics 2019-04-25 Yuya Seki , Shu Tanaka , Shiro Kawabata

Single flux quantum (SFQ) circuitry is a promising candidate for a scalable and integratable cryogenic quantum control system. However, the operation of SFQ circuits introduces non-equilibrium quasiparticles (QPs), which are a significant…

We employ a generalized Dicke model to study theoretically the quantum criticality of an extended two-level atomic ensemble interacting with a single-mode quantized light field. Effective Hamiltonians are derived and diagonalized to…

Quantum Physics · Physics 2007-10-01 Yong Li , Z. D. Wang , C. P. Sun

Quantum phase transitions (QPTs) in qubit systems are known to produce singularities in the entanglement, which could in turn be used to probe the QPT. Current proposals to measure the entanglement are challenging however, because of their…

Mesoscale and Nanoscale Physics · Physics 2013-08-26 Yun-Pil Shim , Sangchul Oh , Jianjia Fei , Xuedong Hu , Mark Friesen

Experimental quantum simulators have become large and complex enough that discovering new physics from the huge amount of measurement data can be quite challenging, especially when little theoretical understanding of the simulated model is…

Quantum Physics · Physics 2020-12-08 Alexander Lidiak , Zhexuan Gong

The transverse Ising Model (TIM) in one dimension is the simplest model which exhibits a quantum phase transition (QPT). Quantities related to quantum information theoretic measures like entanglement, quantum discord (QD) and fidelity are…

Quantum Physics · Physics 2015-05-28 Amit Kumar Pal , Indrani Bose

Quantum supremacy is the ability of quantum processors to outperform classical computers at certain tasks. In digital random quantum circuit approaches for supremacy, the output distribution produced is described by the Porter-Thomas (PT)…

The dynamics of the geometric phase are studied in inhomogeneous quantum spin chains after a quench. Analytic expressions of the Pancharatnam geometric phase (PGP) $\mathcal{G}(t)$ are derived, for both the period-two quantum Ising chain…

Disordered Systems and Neural Networks · Physics 2023-07-19 Kaiyuan Cao , Shuxiang Yang , Yayun Hu , Guangwen Yang

Promising applications of the anisotropic quantum Rabi model (AQRM) in broad parameter ranges are explored, which is realized with superconducting flux qubits simultaneously driven by two-tone time-dependent magnetic fields. Regarding the…

Quantum Physics · Physics 2018-06-01 Yimin Wang , Wen-Long You , Maoxin Liu , Yu-Li Dong , Hong-Gang Luo , G. Romero , J. Q. You

We propose a protocol for two-qubit quantum phase gate based upon reflection of photon pulses from a quantum dot in a cavity. Depending on the state of the quantum dot the reflected photons acquire a conditional phase shift. The key…

Quantum Physics · Physics 2012-12-20 Robert Johne , Andrea Fiore

We uncover a novel dynamical quantum phase transition, using random matrix theory and its associated notion of planar limit. We study it for the isotropic XY Heisenberg spin chain. For this, we probe its real-time dynamics through the…

Quantum Physics · Physics 2024-03-04 David Pérez-García , Leonardo Santilli , Miguel Tierz