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Related papers: Variational quantum thermalizers based on weakly-s…

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We investigate a nonequilibrium quantum thermometry protocol in which an ensemble of qubits, acting as temperature probes, is weakly coupled to a macroscopic thermal bath. The temperature of the bath, the parameter of interest, is encoded…

Quantum Physics · Physics 2026-05-13 Enrico Trombetti , Marco Malitesta , Marco Pezzutto , Stefano Gherardini

We propose a quantum information based scheme to reduce the temperature of quantum many-body systems, and access regimes beyond the current capability of conventional cooling techniques. We show that collective measurements on multiple…

On a quantum superconducting processor we observe partial and infinite-temperature thermalization induced by a sequence of repeated quantum projective measurements, interspersed by a unitary (Hamiltonian) evolution. Specifically, on a qubit…

Quantum Physics · Physics 2023-06-22 Alessandro Santini , Andrea Solfanelli , Stefano Gherardini , Guido Giachetti

Quantum computing holds great promise for solving classically intractable problems such as linear systems and partial differential equations (PDEs). While fully fault-tolerant quantum computers remain out of reach, current noisy…

Quantum Physics · Physics 2025-10-20 Samuel Donachie , Ulysse Remond , Arthur Mathorel , Kyryl Kazymyrenko

We propose using variational quantum algorithms (VQAs) to simulate established quantum algorithms under realistic noise conditions, aiming to surpass the fidelity of theoretical circuits in noisy environments. Focusing on the Quantum…

Variational Quantum Eigensolver (VQE) is widely used in near-term hardware. However, their performances remain limited by the poor trainability and are dependent on random parameter initialization. In this work, we propose a warm start…

Quantum Physics · Physics 2025-12-19 Yahui Chai , Karl Jansen , Stefan Kühn , Tim Schwägerl , Tobias Stollenwerk

We discuss a simple quantum thermal machine for the generation of steady-state entanglement between two interacting qubits. The machine is autonomous in the sense that it uses only incoherent interactions with thermal baths, but no source…

Quantum Physics · Physics 2015-11-25 Jonatan Bohr Brask , Nicolas Brunner , Géraldine Haack , Marcus Huber

The Variational Quantum Eigensolver (VQE) is a Variational Quantum Algorithm (VQA) to determine the ground state of quantum-mechanical systems. As a VQA, it makes use of a classical computer to optimize parameter values for its quantum…

Quantum Physics · Physics 2025-11-13 Felix Truger , Johanna Barzen , Frank Leymann , Julian Obst

A classical thermometer typically works by exchanging energy with the system being measured until it comes to equilibrium, at which point the readout is related to the final energy state of the thermometer. A recent paper noted that…

Quantum Physics · Physics 2016-09-07 W. K. Tham , H. Ferretti , A. V. Sadashivan , A. M. Steinberg

We study the relaxation of a quantum system towards the thermal equilibrium using tools developed within the context of quantum information theory. We consider a model in which the system is a qubit, and reaches equilibrium after several…

Quantum Physics · Physics 2009-11-07 Valerio Scarani , Mario Ziman , Peter Stelmachovic , Nicolas Gisin , Vladimir Buzek

Refrigeration limits are of fundamental and practical importance. We here show that quantum systems can be cooled below existing incoherent cooling bounds by employing coherent virtual qubits, even if the amount of coherence is incompletely…

Quantum Physics · Physics 2024-10-25 Rodolfo R. Soldati , Durga B. R. Dasari , Jörg Wrachtrup , Eric Lutz

Quantum thermal devices which can manage heat as their electronic analogues for the electronic currents have attracted increasing attention. Here a three-terminal quantum thermal device is designed by three coupling qubits interacting with…

Quantum Physics · Physics 2019-03-12 Bao-qing Guo , Tong Liu , Chang-shui Yu

Quantum computing has attracted the attention of the scientific community in the past few decades. However, despite some relevant advantages, near-term quantum devices remain severely limited by thermal effects, which induce decoherence and…

Quantum Physics · Physics 2026-04-02 G. X. A. Petronilo , M. R. Araújo , A. B. M. Souza , Clebson Cruz

Nonunitary quantum operations generating thermostatistical states and forming positive operator-valued measures (POVMs) are of current interest as a useful tool for operational approach to quantum thermodynamics. Here, two different…

Statistical Mechanics · Physics 2015-01-23 Yasuyuki Matsuo , Sumiyoshi Abe

Quantum simulation has begun to penetrate the field of quantum chemistry in hopes of efficiently calculating ground state energies and approximating real-time evolution. With modern research highlighting nonadiabatic dynamics, tunably…

Quantum Physics · Physics 2026-05-08 Joshua M. Courtney , P. C. Stancil

Modeling non-Hermitian Hamiltonians is increasingly important in classical and quantum domains, especially when studying open systems, $PT$ symmetry, and resonances. However, the quantum simulation of these models has been limited by the…

Quantum Physics · Physics 2025-02-20 Anastashia Jebraeilli , Michael R. Geller

Calculating the physical properties of quantum thermal states is a difficult problem for classical computers, rendering it intractable for most quantum many-body systems. A quantum computer, by contrast, would make many of these…

Strongly Correlated Electrons · Physics 2019-11-19 John Martyn , Brian Swingle

The high-speed implementation and robustness against of non-adiabatic holonomic quantum computation provide a new idea for overcoming the difficulty of quantum system interacting with the environment easily decoherence, which realizing…

Quantum Physics · Physics 2020-03-31 Guo-An Yan , Jia-Xin Chen , Hua Lu , Ai-Xi Chen

We revisist the issue of entanglement of thermal equilibrium states in composite quantum systems. The possible scenarios are exemplified in bipartite qubit/qubit and qubit/qutrit systems.

Quantum Physics · Physics 2009-11-11 O. Osenda , G. A. Raggio

Optimizing open quantum system evolution is an important step on the way to achieving quantum computing and quantum thermodynamic tasks. In this article, we approach optimisation via variational principles and derive an open quantum system…

Quantum Physics · Physics 2018-10-17 Nishchay Suri , Felix C. Binder , Bhaskaran Muralidharan , Sai Vinjanampathy