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Related papers: Quantum phase estimation of multiple eigenvalues f…

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Phase estimation, due to Kitaev [arXiv'95], is one of the most fundamental subroutines in quantum computing. In the basic scenario, one is given black-box access to a unitary $U$, and an eigenstate $\lvert \psi \rangle$ of $U$ with unknown…

Quantum Physics · Physics 2025-12-15 Nikhil S. Mande , Ronald de Wolf

Quantum Phase Estimation (QPE) stands as a pivotal quantum computing subroutine that necessitates an inverse Quantum Fourier Transform (QFT). However, it is imperative to recognize that enhancing the precision of the estimation inevitably…

Quantum Physics · Physics 2023-11-09 Chen-Yu Liu , Chu-Hsuan Abraham Lin , Kuan-Cheng Chen

In this work we demonstrate the use of adapted classical phase retrieval algorithms to perform control-free quantum phase estimation. We eliminate the costly controlled time evolution and Hadamard test commonly required to access the…

We introduce a multi-modal, multi-level quantum complex exponential least squares (MM-QCELS) method to simultaneously estimate multiple eigenvalues of a quantum Hamiltonian on early fault-tolerant quantum computers. Our theoretical analysis…

Quantum Physics · Physics 2023-10-18 Zhiyan Ding , Lin Lin

Many quantum algorithms rely on the measurement of complex quantum amplitudes. Standard approaches to obtain the phase information, such as the Hadamard test, give rise to large overheads due to the need for global controlled-unitary…

Quantum Physics · Physics 2024-05-29 Yilun Yang , Arthur Christianen , Mari Carmen Bañuls , Dominik S. Wild , J. Ignacio Cirac

The first generation of multi-qubit quantum technologies will consist of noisy, intermediate-scale devices for which active error correction remains out of reach. To exploit such devices, it is thus imperative to use passive error…

A milestone in the field of quantum computing will be solving problems in quantum chemistry and materials faster than state-of-the-art classical methods. The current understanding is that achieving quantum advantage in this area will…

Quantum Physics · Physics 2023-11-08 Guoming Wang , Daniel Stilck França , Ruizhe Zhang , Shuchen Zhu , Peter D. Johnson

Eigenvalue estimation is a central problem for demonstrating quantum advantage, yet its implementation on digital quantum computers remains limited by circuit depth and operational overhead. We present an analog quantum phase estimation…

Quantum Physics · Physics 2025-06-19 Wei-Chen Lin , Chiao-Hsuan Wang

We present an efficient method for estimating the eigenvalues of a Hamiltonian $H$ from the expectation values of the evolution operator for various times. For a given quantum state $\rho$, our method outputs a list of eigenvalue estimates…

Quantum Physics · Physics 2020-09-08 Rolando D. Somma

The iterative quantum phase estimation algorithm, applied to calculating the ground state energies of quantum chemical systems, is theoretically appealing in its wide scope of being able to handle both weakly and strongly correlated…

Quantum Physics · Physics 2021-11-11 Dipanjali Halder , Srinivasa Prasannaa V. , Valay Agarawal , Rahul Maitra

Measuring global quantum properties-such as the fidelity to complex multipartite states-is both an essential and experimentally challenging task. Classical shadow estimation offers favorable sample complexity, but typically relies on…

Quantum Physics · Physics 2026-02-11 Qingyue Zhang , Dayue Qin , Zhou You , Feng Xu , Jens Eisert , You Zhou

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

While quantum algorithms for simulation exhibit better asymptotic scaling than their classical counterparts, they currently cannot be implemented on real-world devices. Instead, chemists and computer scientists rely on costly classical…

Quantum Physics · Physics 2022-06-03 Christopher Kang , Nicholas P. Bauman , Sriram Krishnamoorthy , Karol Kowalski

Quantum phase estimation combined with Hamiltonian simulation is the most promising algorithmic framework to computing ground state energies on quantum computers. Its main computational overhead derives from the Hamiltonian simulation…

Quantum phase estimation is a core task in quantum technologies ranging from metrology to quantum computing, where it appears as a key subroutine in various algorithms. Here, we quantitatively connect the performance of phase estimation…

Quantum Physics · Physics 2026-05-11 Felix Ahnefeld , Thomas Theurer , Martin B. Plenio

Quantum phase estimation (QPE) of the eigenvalues of a unitary operator on a target quantum system is a crucial subroutine in various quantum algorithms. Conventional QPE is often expensive to implement as it requires a large number of…

Quantum Physics · Physics 2025-02-10 Yuan-De Jin , Shi-Yu Zhang , Wen-Long Ma

Large-scale eigenvalue problems pose a significant challenge to classical computers. While there are efficient quantum algorithms for unitary or Hermitian matrices, eigenvalue problems for non-normal matrices remain open in quantum…

Quantum Physics · Physics 2026-03-25 Honghong Lin , Yun Shang

We introduce a new statistical and variational approach to the phase estimation algorithm (PEA). Unlike the traditional and iterative PEAs which return only an eigenphase estimate, the proposed method can determine any unknown…

Quantum Physics · Physics 2022-02-11 Alexandria J. Moore , Yuchen Wang , Zixuan Hu , Sabre Kais , Andrew M. Weiner

Methods of processing quantum data become more important as quantum computing devices improve their quality towards fault tolerant universal quantum computers. These methods include discrimination and filtering of quantum states given as an…

Quantum Physics · Physics 2020-02-18 D. V. Babukhin , A. A. Zhukov , W. V. Pogosov

This paper is an algorithmic study of quantum phase estimation with multiple eigenvalues. We present robust multiple-phase estimation (RMPE) algorithms with Heisenberg-limited scaling. The proposed algorithms improve significantly from the…

Quantum Physics · Physics 2023-10-26 Haoya Li , Hongkang Ni , Lexing Ying