English
Related papers

Related papers: Variational quantum Gibbs state preparation with a…

200 papers

We propose a method based on deep reinforcement learning that efficiently prepares a quantum many-body pure state in thermal or prethermal equilibrium. The main physical intuition underlying the method is that the information on the…

Quantum Physics · Physics 2023-01-30 Shotaro Z. Baba , Nobuyuki Yoshioka , Yuto Ashida , Takahiro Sagawa

While the preparation of a general quantum state is challenging, realistic problem instances, such as those encountered in quantum chemistry and quantum machine learning-typically exhibit hierarchical amplitude structures, consisting of a…

Quantum Physics · Physics 2026-01-15 Yue Wang , Xiao-Ming Zhang , Xiao Yuan , Qi Zhao

Solving finite-temperature properties of quantum many-body systems is generally challenging to classical computers due to their high computational complexities. In this article, we present experiments to demonstrate a hybrid…

We propose a variational quantum algorithm to prepare ground states of 1D lattice quantum Hamiltonians specifically tailored for programmable quantum devices where interactions among qubits are mediated by Quantum Data Buses (QDB). For…

Quantum Physics · Physics 2020-07-07 Viacheslav V. Kuzmin , Pietro Silvi

The task of learning a quantum circuit to prepare a given mixed state is a fundamental quantum subroutine. We present a variational quantum algorithm (VQA) to learn mixed states which is suitable for near-term hardware. Our algorithm…

Gaussian states hold a fundamental place in quantum mechanics, quantum information, and quantum computing. Many subfields, including quantum simulation of continuous-variable systems, quantum chemistry, and quantum machine learning, rely on…

Quantum Physics · Physics 2026-05-13 Yichen Xie , Nadav Ben-Ami

Solving problems related to open quantum systems has attracted many interests. Here, we propose a variational quantum algorithm to find the steady state of open quantum systems. In this algorithm, we employ parameterized quantum circuits to…

Quantum Physics · Physics 2021-08-11 Huan-Yu Liu , Tai-Ping Sun , Yu-Chun Wu , Guo-Ping Guo

We propose an iterative variational quantum algorithm to simulate the time evolution of arbitrary initial states within a given subspace. The algorithm compresses the Trotter circuit into a shorter-depth parameterized circuit, which is…

Quantum Physics · Physics 2026-02-24 Seung Park , Dongkeun Lee , Jeongho Bang , Hoon Ryu , Kyunghyun Baek

We propose a polynomial-time algorithm for preparing the Gibbs state of the two-dimensional toric code Hamiltonian at any temperature, starting from any initial condition, significantly improving upon prior estimates that suggested…

Quantum Physics · Physics 2025-05-02 Zhiyan Ding , Zeph Landau , Bowen Li , Lin Lin , Ruizhe Zhang

The variational quantum imaginary time evolution (VarQITE) algorithm is a near-term method to prepare the ground state and Gibbs state of Hamiltonians. Finding an appropriate parameterization of the quantum circuit is crucial to the success…

Quantum Physics · Physics 2023-07-26 Xiaoyang Wang , Yahui Chai , Maria Demidik , Xu Feng , Karl Jansen , Cenk Tüysüz

We develop an adaptive method for quantum state preparation that utilizes randomness as an essential component and that does not require classical optimization. Instead, a cost function is minimized to prepare a desired quantum state…

Quantum Physics · Physics 2023-10-10 Alicia B. Magann , Sophia E. Economou , Christian Arenz

Quantum state preparation by adiabatic evolution is currently rendered ineffective by the long implementation times of the underlying quantum circuits, comparable to the decoherence time of present and near-term quantum devices. These…

Quantum Physics · Physics 2022-03-14 E. A. Coello Perez , J. Bonitati , D. Lee , S. Quaglioni , K. A. Wendt

Ubiquitous in quantum computing is the step to encode data into a quantum state. This process is called quantum state preparation, and its complexity for non-structured data is exponential on the number of qubits. Several works address this…

Quantum Physics · Physics 2023-07-28 Israel F. Araujo , Carsten Blank , Ismael C. S. Araújo , Adenilton J. da Silva

We investigate a probe state preparation protocol based on two non-selective generalized quantum measurements to enhance parameter estimation in single-qubit systems. By fine-tuning the measurement strengths, we demonstrate the ability to…

Quantum Physics · Physics 2026-05-13 Jonas F. G. Santos , Shanhe Su , Moises Rojas

Estimating the fidelity of state preparation in multi-qubit systems is generally a time-consuming task. Nevertheless, this complexity can be reduced if the desired state can be characterized by certain symmetries measurable with the…

Quantum Physics · Physics 2009-11-13 R. D. Somma , J. Chiaverini , D. J. Berkeland

We demonstrate a dissipative protocol for ground-state preparation of a quantum spin chain on a trapped-ion quantum computer. As a first step, we derive a Kraus representation of a dissipation channel for the protocol recently proposed by…

Quantum Physics · Physics 2026-01-14 Kazuhiro Seki , Yuta Kikuchi , Tomoya Hayata , Seiji Yunoki

Finding the ground state of a Hamiltonian system is of great significance in many-body quantum physics and quantum chemistry. We propose an improved iterative quantum algorithm to prepare the ground state of a Hamiltonian. The crucial point…

Quantum Physics · Physics 2022-10-25 Jin-Min Liang , Qiao-Qiao Lv , Shu-Qian Shen , Ming Li , Zhi-Xi Wang , Shao-Ming Fei

The conventional method for generating entangled states in qubit systems relies on applying precise two-qubit entangling gates alongside single-qubit rotations. However, achieving high-fidelity entanglement demands high accuracy in…

Highly entangled quantum states are an ingredient in numerous applications in quantum computing. However, preparing these highly entangled quantum states on currently available quantum computers at high fidelity is limited by ubiquitous…

Quantum Physics · Physics 2025-02-27 Sebastian Brandhofer , Ilia Polian , Stefanie Barz , Daniel Bhatti

We introduce a variational approach for preparing low energy states of arbitrary target Hamiltonians. The protocol is defined in terms of a repeated cycle consisting of p layers of unitary gates applied to the system and ancilla "bath"…

Quantum Physics · Physics 2025-10-14 Jeffrey Z. Song , Gilad Kishony , Erez Berg , Mark S. Rudner