Parallel-in-time quantum simulation via Page and Wootters quantum time

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Diaz, N. L., Braccia, Paolo, Larocca, Martin, Matera, J. M., Rossignoli, R., Cerezo, M.
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866914068549337088
author Diaz, N. L.
Braccia, Paolo
Larocca, Martin
Matera, J. M.
Rossignoli, R.
Cerezo, M.
author_facet Diaz, N. L.
Braccia, Paolo
Larocca, Martin
Matera, J. M.
Rossignoli, R.
Cerezo, M.
contents In the past few decades, researchers have created a veritable zoo of quantum algorithms by drawing inspiration from classical computing, information theory, and even from physical phenomena. Here we present quantum algorithms for parallel-in-time simulations that are inspired by the Page and Wootters formalism. In this framework, and thus in our algorithms, the classical time-variable of quantum mechanics is promoted to the quantum realm by introducing a Hilbert space of ``clock'' qubits which are then entangled with the ``system'' qubits. We show that our algorithms can compute temporal properties over $N$ different times of many-body systems by only using $\log(N)$ clock qubits. As such, we achieve an exponential trade-off between time and spatial complexities. In addition, we rigorously prove that the entanglement created between the system qubits and the clock qubits has operational meaning, as it encodes valuable information about the system's dynamics. We also provide a circuit depth estimation of all the protocols, showing a running time advantage in computation times over traditional sequential-in-time algorithms. In particular, for the case when the dynamics are determined by the Aubry--Andre model, we present a hybrid method for which our algorithms have a depth that only scales as $\mathcal{O}(\log(N)n)$. As a by-product, we can relate the previous schemes to the problem of equilibration of an isolated quantum system, thus indicating that our framework enables a new dimension for studying dynamical properties of many-body systems.
format Preprint
id arxiv_https___arxiv_org_abs_2308_12944
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Parallel-in-time quantum simulation via Page and Wootters quantum time
Diaz, N. L.
Braccia, Paolo
Larocca, Martin
Matera, J. M.
Rossignoli, R.
Cerezo, M.
Quantum Physics
Computation
In the past few decades, researchers have created a veritable zoo of quantum algorithms by drawing inspiration from classical computing, information theory, and even from physical phenomena. Here we present quantum algorithms for parallel-in-time simulations that are inspired by the Page and Wootters formalism. In this framework, and thus in our algorithms, the classical time-variable of quantum mechanics is promoted to the quantum realm by introducing a Hilbert space of ``clock'' qubits which are then entangled with the ``system'' qubits. We show that our algorithms can compute temporal properties over $N$ different times of many-body systems by only using $\log(N)$ clock qubits. As such, we achieve an exponential trade-off between time and spatial complexities. In addition, we rigorously prove that the entanglement created between the system qubits and the clock qubits has operational meaning, as it encodes valuable information about the system's dynamics. We also provide a circuit depth estimation of all the protocols, showing a running time advantage in computation times over traditional sequential-in-time algorithms. In particular, for the case when the dynamics are determined by the Aubry--Andre model, we present a hybrid method for which our algorithms have a depth that only scales as $\mathcal{O}(\log(N)n)$. As a by-product, we can relate the previous schemes to the problem of equilibration of an isolated quantum system, thus indicating that our framework enables a new dimension for studying dynamical properties of many-body systems.
title Parallel-in-time quantum simulation via Page and Wootters quantum time
topic Quantum Physics
Computation
url https://arxiv.org/abs/2308.12944