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

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A spatially-selective and internal-state-selective triggering pulse is an important component to realize the unitary dynamical state-locking process which may be used to realize the reversible and unitary halting protocol and construct the…

Quantum Physics · Physics 2013-09-18 Xijia Miao

We introduce a phenomenological theory for many-body control of critical phenomena by engineering causally-induced gaps for quantum Hamiltonian systems. The core mechanisms are controlling information flow within and/or between clusters…

Quantum Physics · Physics 2018-10-22 Masoud Mohseni , Johan Strumpfer , Marek M. Rams

The generation of certifiable randomness is one of the most promising applications of quantum technologies. Furthermore, the intrinsic non-locality of quantum correlations allow us to certify randomness in a device-independent way, i.e. one…

Quantum Physics · Physics 2020-08-04 Brian Coyle , Elham Kashefi , Matty Hoban

Holographic duality is a powerful tool to investigate the far-from equilibrium dynamics of superfluids and other phases of quantum matter. For technical reasons it is usually assumed that, after a quench, the far-from equilibrium fields are…

High Energy Physics - Theory · Physics 2015-06-17 Antonio M. García-García , Hua Bi Zeng , Hai Qing Zhang

Recent advances in quantum simulators allow direct experimental access to ensembles of pure states generated by measuring part of an isolated quantum many-body system. These projected ensembles encode fine-grained information beyond thermal…

Quantum Physics · Physics 2026-01-26 Wai-Keong Mok , Tobias Haug , Wen Wei Ho , John Preskill

We present a scheme for quantum random-number generation from an untrusted measurement device and a trusted source and demonstrate it experimentally. No assumptions about noise or imperfections in the measurement are required, and the…

Quantum Physics · Physics 2022-10-26 Kieran Neil Wilkinson , Casper Ahl Breum , Tobias Gehring , Jonatan Bohr Brask

Chaotic behavior of quantum systems can be characterized by the adherence of the expectation values of given probes to moments of the Haar distribution. In this work, we analyze the behavior of several probes of chaos using a technique…

Quantum Physics · Physics 2026-04-14 Stefano Cusumano , Gianluca Esposito , Alioscia Hamma

This paper presents the design and analysis of a Hybrid High-Order (HHO) approximation for a distributed optimal control problem governed by the Poisson equation. We propose three distinct schemes to address unconstrained control problems…

Numerical Analysis · Mathematics 2025-01-14 Gouranga Mallik , Ramesh Chandra Sau

We introduce a protocol for the fast simulation of $n$-dimensional quantum systems on $n$-qubit quantum computers with tunable couplings. A mapping is given between the control parameters of the quantum computer and the matrix elements of…

We demonstrate how structured decompositions of unitary operators can be employed to derive control schemes for finite-level quantum systems that require only sequences of simple control pulses such as square wave pulses with finite rise…

Quantum Physics · Physics 2009-11-07 S. G. Schirmer , A. D. Greentree , V. Ramakrishna , H. Rabitz

Time crystals in periodically driven systems have initially been studied assuming either the ability to quench the Hamiltonian between different many-body regimes, the presence of disorder or long-range interactions. Here we propose the…

The correlated non-equilibrium dynamics of few-boson systems in one-dimensional finite lattices is investigated. Starting from weak interactions we perform a sudden interaction quench and employ the numerically exact Multi-Layer…

Quantum Gases · Physics 2017-10-31 S. I. Mistakidis , L. Cao , P. Schmelcher

We present a general control-theoretic framework for constructing and analyzing random decoupling schemes, applicable to quantum dynamical control of arbitrary finite-dimensional composite systems. The basic idea is to design the control…

Quantum Physics · Physics 2009-11-11 Lorenza Viola , Emanuel Knill

Quantum walk research has mainly focused on evolutions due to repeated applications of time-independent unitary coin operators. However, the idea of controlling the single particle evolution using time-dependent unitary coins has still been…

Quantum Physics · Physics 2019-09-19 Shrabanti Dhar , Abdul Khaleque , Tushar Kanti Bose

Dynamical decoupling techniques constitute an integral part of many quantum sensing platforms, often leading to orders-of-magnitude improvements in coherence time and sensitivity. Most AC sensing sequences involve a periodic echo-like…

High harmonic generation (HHG) provides a flexible framework for the development of coherent light sources in the extreme-ultraviolet and soft x-ray regimes. However it suffers from low conversion efficiencies as the control of the HHG…

Optics · Physics 2014-09-16 Alberto Castro , Angel Rubio , E. K. U. Gross

We give an explicit stochastic Hamiltonian model of discontinuous unitary evolution for quantum spontaneous jumps like in a system of atoms in quantum optics, or in a system of quantum particles that interacts singularly with "bubbles"…

Quantum Physics · Physics 2009-11-11 V. P. Belavkin , O. Melsheimer

This paper concerns a class of uncertain linear quantum systems subject to quadratic perturbations in the system Hamiltonian. A small gain approach is used to evaluate the performance of the given quantum system. In order to get improved…

Systems and Control · Computer Science 2015-08-12 Chengdi Xiang , Ian R. Petersen , Daoyi Dong

Quench spectroscopy is a relatively new method which enables the investigation of spectral properties of many-body quantum systems by monitoring the out-of-equilibrium dynamics of real-space observables after a quench. So far the approach…

Quantum Gases · Physics 2020-10-07 L. Villa , J. Despres , S. J. Thomson , L. Sanchez-Palencia

In our model a fixed Hamiltonian acts on the joint Hilbert space of a quantum system and its controller. We show under which conditions measurements, state preparations, and unitary implementations on the system can be performed by quantum…

Quantum Physics · Physics 2009-11-07 Dominik Janzing , Frederik Armknecht , Robert Zeier , Thomas Beth