https://doi.org/10.1140/epjd/e2002-00127-x
Eigenstates of an operating quantum computer: hypersensitivity to static imperfections
1
International Center for the Study of Dynamical
Systems, Università degli Studi dell'Insubria and
Istituto Nazionale per la Fisica della Materia,
Unità di Como, Via Valleggio 11, 22100 Como, Italy
2
Istituto Nazionale di Fisica Nucleare,
Sezione di Milano, Via Celoria 16, 20133 Milano, Italy
3
Laboratoire de Physique Quantique (UMR 5626 du CNRS) ,
Université Paul Sabatier, 31062 Toulouse Cedex 4, France
Corresponding author: a benenti@fis.unico.it
Received:
7
March
2002
Revised:
3
May
2002
Published online:
19
July
2002
We study the properties of eigenstates of an operating quantum computer which simulates the dynamical evolution in the regime of quantum chaos. Even if the quantum algorithm is polynomial in number of qubits nq, it is shown that the ideal eigenstates become mixed and strongly modified by static imperfections above a certain threshold which drops exponentially with nq. Above this threshold the quantum eigenstate entropy grows linearly with nq but the computation remains reliable during a time scale which is polynomial in the imperfection strength and in nq.
PACS: 03.67.Lx – Quantum computation / 05.45.Mt – Semiclassical chaos (“quantum chaos”) / 24.10.Cn – Many-body theory
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002