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Related papers: Realizing Unitary $k$-designs with a Single Quench

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Quantum ensemble systems arise in a variety of applications, including NMR spectroscopy and robust quantum control. While their theoretical properties have been extensively studied, relatively little attention has been given to the explicit…

Optimization and Control · Mathematics 2025-06-25 Ruikang Liang , Gong Cheng

The notion of topological phases extended to dynamical systems stimulates extensive studies, of which the characterization of non-equilibrium topological invariants is a central issue and usually necessitates the information of quantum…

Quantum Physics · Physics 2021-10-11 Danying Yu , Bo Peng , Xianfeng Chen , Xiong-Jun Liu , Luqi Yuan

We present a quantum algorithm for simulating the time evolution generated by any bounded, time-dependent operator $-A$ with non-positive logarithmic norm, thereby serving as a natural generalization of the Hamiltonian simulation problem.…

Quantum Physics · Physics 2025-09-15 Guang Hao Low , Rolando D. Somma

Non-autonomous dynamical systems appear in a very wide range of interesting applications, both in classical and quantum dynamics, where in the latter case it corresponds to having a time-dependent Hamiltonian. However, the quantum…

Quantum Physics · Physics 2025-04-22 Yu Cao , Shi Jin , Nana Liu

We introduce a method to perform imaginary time evolution in a controllable quantum system using measurements and conditional unitary operations. By performing a sequence of weak measurements based on the desired Hamiltonian constructed by…

We study the topological properties of one dimensional systems undergoing unitary time evolution. We show that symmetries possessed both by the initial wavefunction and by the Hamiltonian at all times may not be present in the…

Mesoscale and Nanoscale Physics · Physics 2018-09-12 Max McGinley , Nigel R. Cooper

A sudden change of the Hamiltonian parameter drives a quantum system out of equilibrium. For a finite-size system, expectations of observables start fluctuating in time without converging to a precise limit. A new equilibrium state emerges…

Quantum Physics · Physics 2013-03-21 Lorenzo Campos Venuti , Paolo Zanardi

We propose dynamical control schemes for Hamiltonian simulation in many-body quantum systems that avoid instantaneous control operations and rely solely on realistic bounded-strength control Hamiltonians. Each simulation protocol consists…

Quantum Physics · Physics 2014-06-25 Adam D. Bookatz , Pawel Wocjan , Lorenza Viola

We consider a quantum quench in which two initially independent condensates are suddenly coupled, and study the subsequent "rephasing" dynamics. For weak couplings, the time-evolution of physical observables is predicted to follow universal…

Quantum Gases · Physics 2013-04-18 Emanuele G. Dalla Torre , Eugene Demler , Anatoli Polkovnikov

While quantum speed-up in solving certain decision problems by a fault-tolerant universal quantum computer has been promised, a timely research interest includes how far one can reduce the resource requirement to demonstrate a provable…

Quantum Physics · Physics 2018-01-01 Jacob Miller , Stephen Sanders , Akimasa Miyake

Using a Luttinger liquid theory we investigate the time evolution of the particle density of a one-dimensional fermionic system with open boundaries and subject to a finite duration quench of the inter-particle interaction. We provide…

Strongly Correlated Electrons · Physics 2016-08-16 S. Porta , F. M. Gambetta , F. Cavaliere , N. Traverso Ziani , M. Sassetti

Unitary $t$-designs are the bread and butter of quantum information theory and beyond. An important issue in practice is that of efficiently constructing good approximations of such unitary $t$-designs. Building on results by Aubrun (Comm.…

Quantum Physics · Physics 2020-09-02 Cécilia Lancien , Christian Majenz

It is shown that if one can perform a restricted set of fast manipulations on a quantum system, one can implement a large class of dynamical evolutions by effectively removing or introducing selected Hamiltonians. The procedure can be used…

Quantum Physics · Physics 2009-01-23 Lorenza Viola , Seth Lloyd , Emanuel Knill

We propose and experimentally demonstrate the \emph{Quasi-Superposition Quantum-inspired System (QSQS)} -- a conceptual quantum system for randomness generation built on measuring two conjugate observables of a permutation sorting process:…

Quantum Physics · Physics 2025-11-06 Randy Kuang

We study the time-evolution of cumulants of velocities and kinetic energies in the stochastic Kac model for velocity exchange of $N$ particles, with the aim of quantifying how fast these degrees of freedom become chaotic in a time scale in…

Mathematical Physics · Physics 2025-01-31 Jani Lukkarinen , Aleksis Vuoksenmaa

Recent studies have identified materials and devices whose behavior lies beyond the scope of conventional electronic-structure theory. Such theories are formulated entirely in terms of Hamiltonian evolution and therefore describe only…

Statistical Mechanics · Physics 2026-03-24 Jochen Mannhart

Producing quantum states at random has become increasingly important in modern quantum science, with applications both theoretical and practical. In particular, ensembles of such randomly-distributed, but pure, quantum states underly our…

We present a theoretical method to generate a highly accurate {\em time-independent} Hamiltonian governing the finite-time behavior of a time-periodic system. The method exploits infinitesimal unitary transformation steps, from which…

Statistical Mechanics · Physics 2019-05-30 Michael Vogl , Pontus Laurell , Aaron D. Barr , Gregory A. Fiete

Characterizing quantum systems by learning their underlying Hamiltonians is a central task in quantum information science. While recent algorithmic advances have achieved near-optimal efficiency in this task, they critically rely on…

Quantum Physics · Physics 2026-05-01 Myeongjin Shin , Junseo Lee , Changhun Oh

The search for exotic temporal orders in quantum matter, such as discrete quasi-time crystals (DQTCs), has become an important theme in nonequilibrium physics. However, realizing these phases has so far required complex protocols, such as…

Quantum Physics · Physics 2025-12-12 Xu Feng , Shuo Liu , Shu Chen , Shi-Xin Zhang