Universal algorithm for transforming Hamiltonian eigenvalues

Bibliographic Details
Title: Universal algorithm for transforming Hamiltonian eigenvalues
Authors: Odake, Tatsuki, Kristjánsson, Hlér, Taranto, Philip, Murao, Mio
Source: Phys. Rev. Research 7, 013331 (2025)
Publication Year: 2023
Collection: Quantum Physics
Subject Terms: Quantum Physics
Description: Manipulating Hamiltonians governing physical systems has found a broad range of applications, from quantum chemistry to semiconductor design. In this work, we provide a new way of manipulating Hamiltonians, by transforming their eigenvalues while keeping their eigenstates unchanged. We develop a universal algorithm that deterministically implements any desired (suitably differentiable) function on the eigenvalues of any unknown Hamiltonian, whose positive-time and negative-time dynamics are given as a black box. Our algorithm uses correlated randomness to efficiently combine two subroutines -- namely controlization and Fourier series simulation -- exemplifying a general compilation procedure that we develop. The time complexity of our algorithm is significantly reduced via said compilation technique compared to a na{\"i}ve concatenation of the subroutines and outperforms similar methods based on the quantum singular value transformation.
Comment: 12+23 pages, 14 figures, close to published version. Note that a previous version of this article [v4] contains an algorithm to implement negative-time Hamiltonian dynamics without any auxilliary systems
Document Type: Working Paper
DOI: 10.48550/arXiv.2312.08848
Access URL: http://arxiv.org/abs/2312.08848
Accession Number: edsarx.2312.08848
Database: arXiv
Description
DOI:10.48550/arXiv.2312.08848