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Extracting useful work from quantum systems is a fundamental problem in quantum thermodynamics. In scenarios where rapid protocols are desired -- whether due to practical constraints or deliberate design choices -- a fundamental trade-off…

Quantum Physics · Physics 2026-04-23 Shoki Sugimoto , Takahiro Sagawa , Ryusuke Hamazaki

All elementary Hamiltonians in nature are expected to be invariant under rotation. Despite this restriction, we usually assume that any arbitrary measurement or unitary time evolution can be implemented on a physical system, an assumption…

Quantum Physics · Physics 2009-11-13 I. Marvian , R. B. Mann

We introduce a family of identities that express general linear non-unitary evolution operators as a linear combination of unitary evolution operators, each solving a Hamiltonian simulation problem. This formulation can exponentially…

Quantum Physics · Physics 2025-12-16 Dong An , Andrew M. Childs , Lin Lin

We have studied quantum systems on finite-dimensional Hilbert spaces and found that all these systems are connected through local transformations. Actually, we have shown that these transformations give rise to a gauge group that connects…

General Physics · Physics 2023-08-28 M. Caruso

In quantum adiabatic evolution algorithms, the quantum computer follows the ground state of a slowly varying Hamiltonian. The ground state of the initial Hamiltonian is easy to construct; the ground state of the final Hamiltonian encodes…

Quantum Physics · Physics 2007-05-23 Edward Farhi , Jeffrey Goldstone , Sam Gutmann

Simulation of quantum systems is notoriously challenging for classical computers, while quantum hardware is naturally well-suited for this task. However, the imperfections of contemporary quantum systems poses a considerable challenge in…

Quantum Physics · Physics 2025-01-10 Yotam Shapira , Jovan Markov , Nitzan Akerman , Ady Stern , Roee Ozeri

Hamiltonian learning protocols are essential tools to benchmark quantum computers and simulators. Yet rigorous methods for time-dependent Hamiltonians and Lindbladians remain scarce despite their wide use. We close this gap by learning the…

Quantum Physics · Physics 2025-10-10 Daniel Stilck França , Tim Möbus , Cambyse Rouzé , Albert H. Werner

Exactly solvable Hamiltonians are useful in the study of quantum many-body systems using quantum computers. In the variational quantum eigensolver, a decomposition of the target Hamiltonian into exactly solvable fragments can be used for…

Quantum Physics · Physics 2024-02-15 Smik Patel , Artur F. Izmaylov

When a Hamiltonian system is subject to constraints which depend explicitly on time, difficulties can arise in attempting to reduce the system to its physical phase space. Specifically, it is non-trivial to restrict the system in such a way…

High Energy Physics - Theory · Physics 2015-06-26 Jonathan M. Evans , Philip A. Tuckey

We reelaborate on a general method for diagonalizing a wide class of nonlinear Hamiltonians describing different quantum optical models. This method makes use of a nonlinear deformation of the usual su(2) algebra and when some physical…

Quantum Physics · Physics 2007-05-23 A. B. Klimov , A. Navarro , L. L. Sanchez-Soto

Hamiltonian matrices appear in a variety or problems in physics and engineering, mostly related to the time evolution of linear dynamical systems as for instance in ion beam optics. The time evolution is given by symplectic transfer…

General Physics · Physics 2018-02-20 C. Baumgarten

Hamiltonian dynamics describe a wide range of physical systems. As such, data-driven simulations of Hamiltonian systems are important for many scientific and engineering problems. In this work, we propose kernel-based methods for…

Numerical Analysis · Mathematics 2025-09-23 Yasamin Jalalian , Mostafa Samir , Boumediene Hamzi , Peyman Tavallali , Houman Owhadi

We present a quantum algorithm based on repeated measurement to solve initial-value problems for nonlinear ordinary differential equations (ODEs), which may be generated from partial differential equations in plasma physics. We map a…

Quantum Physics · Physics 2025-04-30 Joseph Andress , Alexander Engel , Yuan Shi , Scott Parker

We provide a quantum method for simulating Hamiltonian evolution with complexity polynomial in the logarithm of the inverse error. This is an exponential improvement over existing methods for Hamiltonian simulation. In addition, its scaling…

Quantum Physics · Physics 2013-10-24 Dominic W. Berry , Richard Cleve , Rolando D. Somma

We describe a general method to identify exact, local parent Hamiltonians for trial states like quantum Hall or spin liquid states, which we have used extensively during the past decade. It can be used to identify exact parent Hamiltonians,…

Strongly Correlated Electrons · Physics 2018-08-29 Martin Greiter , Vera Schnells , Ronny Thomale

The quantum description of time evolution in non-linear gravitational systems such as cosmological space-times is not well understood. We show, in the simplified setting of mini-superspace, that time evolution of this system can be obtained…

General Relativity and Quantum Cosmology · Physics 2023-05-02 Anne-Katherine Burns , David E. Kaplan , Tom Melia , Surjeet Rajendran

By using the effective Hamiltonian approach, we present a self-consistent framework for the analysis of geometric phases and dynamically stable decoherence-free subspaces in open systems. Comparisons to the earlier works are made. This…

Quantum Physics · Physics 2009-11-13 X. L. Huang , X. X. Yi , Chunfeng Wu , X. L. Feng , S. X. Yu , C. H. OH

Extensive N-body simulations are among the key means for the study of numerous astrophysical and cosmological phenomena, so various schemes are developed for possibly higher accuracy computations. We demonstrate the principal possibility…

Instrumentation and Methods for Astrophysics · Physics 2018-11-05 V. G. Gurzadyan , V. V. Harutyunyan , A. A. Kocharyan

Electronic structure simulation is an anticipated application for quantum computers. Due to high-dimensional quantum entanglement in strongly correlated systems, the quantum resources required to perform such simulations are far beyond the…

Quantum Physics · Physics 2022-01-25 Jie Liu , Zhenyu Li , Jinlong Yang

An effective Hamiltonian describing interaction between generic "fast" and a "slow" systems is obtained in the strong interaction limit. The result is applied for studying the effect of quantum phase transition as a bifurcation of the…

Quantum Physics · Physics 2009-11-13 Isabel Sainz , Andrei B. Klimov , Luis Roa