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Related papers: Multiple-time Quantum Imaginary Time Evolution

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Quantum state preparation plays a crucial role in several areas of quantum information science, in applications such as quantum simulation, quantum metrology and quantum computing. However, typically state preparation requires resources…

Quantum Physics · Physics 2024-12-11 Tianqi Chen , Tim Byrnes

Dynamic quantum circuits combine mid-circuit measurement with classical feed-forward, enabling circuit constructions with reduced entangling-gate depth. Here, we investigate their use in Quantum Imaginary Time Evolution (QITE), where…

Quantum Physics · Physics 2026-03-06 Albert Lund , Erika Magnusson , Werner Dobrautz , Laura García-Álvarez

Quantum optimization algorithms offer a promising route to finding the ground states of target Hamiltonians on near-term quantum devices. None the less, it remains necessary to limit the evolution time and circuit depth as much as possible,…

Quantum Physics · Physics 2022-11-01 Chenfeng Cao , Yunlong Yu , Zipeng Wu , Nic Shannon , Bei Zeng , Robert Joynt

The preparation of Hamiltonian eigenstates is essential for many applications in quantum computing; the efficiency with which this can be done is of key interest. A canonical approach exploits the quantum phase estimation (QPE) algorithm.…

Quantum Physics · Physics 2022-12-05 Richard Meister , Simon C. Benjamin

Numerous methodologies have been proposed to implement imaginary time evolution (ITE) on quantum computers. Among these, variational ITE (VITE) methods for noisy intermediate-scale quantum (NISQ) computers have attracted much attention,…

Quantum Physics · Physics 2025-11-26 Hiroki Kuji , Tetsuro Nikuni , Yuta Shingu

Imaginary-time evolution has been shown to be a promising framework for tackling combinatorial optimization problems on quantum hardware. In this work, we propose a classical quantum-inspired strategy for solving combinatorial optimization…

Quantum Physics · Physics 2025-12-05 Erik M. Åsgrim , Ahsan Javed Awan

In this work we present a detailed analysis of variational quantum phase estimation (VQPE), a method based on real-time evolution for ground and excited state estimation on near-term hardware. We derive the theoretical ground on which the…

The time evolution operator plays a crucial role in the precise computation of chemical experiments on quantum computers and holds immense promise for advancing the fields of physical and computer sciences, with applications spanning…

Various methods have been developed for the quantum computation of the ground and excited states of physical and chemical systems, but many of them require either large numbers of ancilla qubits or high-dimensional optimization. The quantum…

Quantum Physics · Physics 2019-12-16 Kübra Yeter-Aydeniz , Raphael C. Pooser , George Siopsis

Quantum computers have been widely speculated to offer significant advantages in obtaining the ground state of difficult Hamiltonian in chemistry and physics. In this work, we first propose a Lyapunov control-inspired strategy to accelerate…

Quantum Physics · Physics 2022-12-21 Yu-Cheng Chen , Yu-Qin Chen , Alice Hu , Chang-Yu Hsieh , Shengyu Zhang

Efficient low-energy state preparation is a key objective in quantum computation and quantum simulation. Quantum imaginary-time evolution replaces real-time dynamics with imaginary-time dynamics, exponentially suppressing higher-energy…

Quantum Physics · Physics 2026-03-13 Tal Schwartzman , Torsten V. Zache , Hannes Pichler , H. R. Sadeghpour

The quantum imaginary time evolution is a powerful algorithm for preparing the ground and thermal states on near-term quantum devices. However, algorithmic errors induced by Trotterization and local approximation severely hinder its…

Quantum Physics · Physics 2022-03-16 Chenfeng Cao , Zheng An , Shi-Yao Hou , D. L. Zhou , Bei Zeng

Excited states of many-body quantum systems play a key role in a wide range of physical and chemical phenomena. Unlike ground states, for which many efficient variational techniques exist, there are few ways to systematically construct…

Quantum Physics · Physics 2025-08-04 D. A. Millar , L. W. Anderson , E. Altamura , O. Wallis , M. E. Sahin , J. Crain , S. J. Thomson

Under suitable assumptions, the algorithms in [Lin, Tong, Quantum 2020] can estimate the ground state energy and prepare the ground state of a quantum Hamiltonian with near-optimal query complexities. However, this is based on a block…

Quantum Physics · Physics 2022-10-19 Yulong Dong , Lin Lin , Yu Tong

In this study, we employed a quantum computer to solve a low-energy effective Hamiltonian for spin defects in diamond (so-called NV centre) and wurtzite-type aluminium nitride, which are anticipated to be qubits. The probabilistic…

The real- and imaginary-time evolution of quantum states are powerful tools in physics, chemistry, and beyond, to investigate quantum dynamics, prepare ground states or calculate thermodynamic observables. On near-term devices, variational…

Quantum Physics · Physics 2024-02-27 Julien Gacon , Jannes Nys , Riccardo Rossi , Stefan Woerner , Giuseppe Carleo

We propose an imaginary time equivalent of the well-established Pauli gadget primitive for Trotter-decomposed real time evolution, using mid-circuit measurements on a single ancilla qubit. Imaginary time evolution (ITE) is widely used for…

Quantum Physics · Physics 2023-10-31 Chiara Leadbeater , Nathan Fitzpatrick , David Muñoz Ramo , Alex J. W. Thom

Imaginary-time evolution is a standard primitive for ground-state preparation but is nonunitary, precluding direct quantum implementation. We develop Finite Imaginary-Time Evolution (FinITE), a finite-beta construction for diagonal Pauli-Z…

Quantum Physics · Physics 2026-05-01 Jaehee Kim , Juhyeon Kim , Gwonhak Lee , Kyunghyun Baek , Daniel K. Park , Jeongho Bang , Joonsuk Huh

Imaginary Time Evolution (QITE) approximates this evolution on quantum hardware but suffers from high circuit depth and numerous measurements. In this work we introduce Adaptive-time Compressed QITE (ACQ), a novel algorithm that reduces…

For quantum state preparation, a non-unitary operator is typically designed to decay undesirable states contained in an initial state using ancilla qubits and a probabilistic action. Probabilistic algorithms do not accelerate the…

Quantum Physics · Physics 2023-08-22 Hirofumi Nishi , Taichi Kosugi , Yusuke Nishiya , Yu-ichiro Matsushita