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We study the transition probabilities of a two-point measurement on a quantum system, initially prepared in a thermal state. We find two independent constraints on the difference between transition probabilities when the system is prepared…

Mesoscale and Nanoscale Physics · Physics 2025-05-20 Ludovico Tesser , Matteo Acciai , Christian Spånslätt , Inès Safi , Janine Splettstoesser

Connections between the resource theories of coherence and purity (or non-uniformity) are well known for discrete-variable, finite-dimensional, quantum systems. We establish analogous results for continuous-variable systems, in particular…

Quantum Physics · Physics 2021-11-17 Giulio Gianfelici , Hermann Kampermann , Dagmar Bruß

Pseudorandom quantum states (PRS) are efficiently constructible states that are computationally indistinguishable from being Haar-random, and have recently found cryptographic applications. We explore new definitions, new properties and…

Quantum Physics · Physics 2023-06-12 Prabhanjan Ananth , Aditya Gulati , Luowen Qian , Henry Yuen

Quantum entanglement is considered, by and large, to be a very delicate and non-robust phenomenon that is very hard to maintain in the presence of noise, or non-zero temperatures. In recent years however, and motivated, in part, by a quest…

Quantum Physics · Physics 2017-02-27 Lior Eldar

Understanding the complexity of quantum states and circuits is a central challenge in quantum information science, with broad implications in many-body physics, high-energy physics and quantum learning theory. A common way to model the…

Quantum Physics · Physics 2026-05-15 Oxana Shaya , Zoë Holmes , Christoph Hirche , Armando Angrisani

Hamiltonian systems of ordinary and partial differential equations are fundamental mathematical models spanning virtually all physical scales. A critical property for the robustness and stability of computational methods in such systems is…

Quantum Physics · Physics 2025-02-25 Hsuan-Cheng Wu , Xiantao Li

We study how conservation laws shape the spreading of quantum coherence in many-body dynamics. Focusing on $U(1)$-symmetric random circuits, charge-and-dipole conserving circuits, as well as ergodic Hamiltonian dynamics, we probe coherences…

Quantum Physics · Physics 2026-04-28 Sreemayee Aditya , Emanuele Tirrito , Piotr Sierant , Xhek Turkeshi

We develop a framework to describe how quantum coherences between distinct charge sectors evolve under generic charge-conserving dynamics. Our framework captures the nonperturbative interactions between quantum coherences and hydrodynamic…

Quantum Physics · Physics 2026-05-01 Ewan McCulloch , J. Alexander Jacoby , Sarang Gopalakrishnan

Many quantum information protocols require the implementation of random unitaries. Because it takes exponential resources to produce Haar-random unitaries drawn from the full $n$-qubit group, one often resorts to $t$-designs. Unitary…

The realization of unitary designs is of fundamental interest in quantum science and typically requires the ability to implement structured quantum circuits. Recent developments have explored the possibility of generating unitary designs…

Quantum Physics · Physics 2026-04-14 Ning Sun , Pengfei Zhang

Quantum pseudorandomness has found applications in many areas of quantum information, ranging from entanglement theory, to models of scrambling phenomena in chaotic quantum systems, and, more recently, in the foundations of quantum…

Quantum Physics · Physics 2025-07-23 John Bostanci , Jonas Haferkamp , Dominik Hangleiter , Alexander Poremba

Deep thermalization refers to the emergence of Haar-like randomness from quantum systems upon partial measurements. As a generalization of quantum thermalization, it is often associated with high complexity and entanglement. Here, we…

Quantum Physics · Physics 2025-11-24 Shantanav Chakraborty , Soonwon Choi , Soumik Ghosh , Tudor Giurgică-Tiron

We investigate circuit complexity of unitaries generated by time evolution of randomly chosen strongly interacting Hamiltonians in finite dimensional Hilbert spaces. Specifically, we focus on two ensembles of random generators -- the so…

Quantum Physics · Physics 2025-03-04 Marcin Kotowski , Michał Oszmaniec , Michał Horodecki

(i) We point out that every local unitary circuit of depth smaller than the linear system size is easily distinguished from a global Haar random unitary if there is a conserved quantity that is a sum of local operators. This is always the…

Quantum Physics · Physics 2025-12-17 Jeongwan Haah

Estimating the eigenvalues of a unitary transformation U by standard phase estimation requires the implementation of controlled-U-gates which are not available if U is only given as a black box. We show that a simple trick allows to measure…

Quantum Physics · Physics 2007-05-23 Dominik Janzing , Thomas Beth

Random circuits giving rise to unitary designs are key tools in quantum information science and many-body physics. In this work, we investigate a class of random quantum circuits with a specific gate structure. Within this framework, we…

Imaginary time evolution is a powerful tool applied in quantum physics, while existing classical algorithms for simulating imaginary time evolution suffer high computational complexity as the quantum systems become larger and more complex.…

Quantum Physics · Physics 2022-10-12 Hao-Nan Xie , Shi-Jie Wei , Fan Yang , Zheng-An Wang , Chi-Tong Chen , Heng Fan , Gui-Lu Long

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be complex. Here, based on energy variance, we propose a variational method for solving the…

Quantum Physics · Physics 2024-02-21 Xu-Dan Xie , Zheng-Yuan Xue , Dan-Bo Zhang

Local master equations are a widespread tool to model open quantum systems, especially in the context of many-body systems. These equations, however, are believed to lead to thermodynamic anomalies and violation of the laws of…

Quantum Physics · Physics 2021-02-23 Adam Hewgill , Gabriele De Chiara , Alberto Imparato

Estimation of the energy of quantum many-body systems is a paradigmatic task in various research fields. In particular, efficient energy estimation may be crucial in achieving a quantum advantage for a practically relevant problem. For…

Quantum Physics · Physics 2025-02-11 Alexander Gresch , Martin Kliesch