Quantum Circuit for Non-Unitary Linear Transformation of Basis Sets

Fuente: arXiv
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Main Authors: Zhu, Guorui, Bierman, Joel, Lu, Jianfeng, Li, Yingzhou
Format: Preprint
Published: 2025
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author Zhu, Guorui
Bierman, Joel
Lu, Jianfeng
Li, Yingzhou
author_facet Zhu, Guorui
Bierman, Joel
Lu, Jianfeng
Li, Yingzhou
contents This paper introduces a novel approach to implementing non-unitary linear transformations of basis on quantum computational platforms, a significant leap beyond the conventional unitary methods. By integrating Singular Value Decomposition (SVD) into the process, the method achieves an operational depth of $O(n)$ with about $n$ ancilla qubits, enhancing the computational capabilities for analyzing fermionic systems. The non-unitarity of the transformation allows us to transform a wave function from one basis to another, which can span different spaces. By this trick, we can calculate the overlap of two wavefunctions that live in different (but non-distinct Hilbert subspaces) with different basis representations. This provides the opportunity to use state specific ansatzes to calculate different energy eigenstates under orbital-optimized settings and may improve the accuracy when computing the energies of multiple eigenstates simultaneously in VQE or other framework. It allows for a deeper exploration of complex quantum states and phenomena, expanding the practical applications of quantum computing in physics and chemistry.
format Preprint
id arxiv_https___arxiv_org_abs_2502_08962
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantum Circuit for Non-Unitary Linear Transformation of Basis Sets
Zhu, Guorui
Bierman, Joel
Lu, Jianfeng
Li, Yingzhou
Quantum Physics
This paper introduces a novel approach to implementing non-unitary linear transformations of basis on quantum computational platforms, a significant leap beyond the conventional unitary methods. By integrating Singular Value Decomposition (SVD) into the process, the method achieves an operational depth of $O(n)$ with about $n$ ancilla qubits, enhancing the computational capabilities for analyzing fermionic systems. The non-unitarity of the transformation allows us to transform a wave function from one basis to another, which can span different spaces. By this trick, we can calculate the overlap of two wavefunctions that live in different (but non-distinct Hilbert subspaces) with different basis representations. This provides the opportunity to use state specific ansatzes to calculate different energy eigenstates under orbital-optimized settings and may improve the accuracy when computing the energies of multiple eigenstates simultaneously in VQE or other framework. It allows for a deeper exploration of complex quantum states and phenomena, expanding the practical applications of quantum computing in physics and chemistry.
title Quantum Circuit for Non-Unitary Linear Transformation of Basis Sets
topic Quantum Physics
url https://arxiv.org/abs/2502.08962