Cleve, Richard ;
Wang, Chunhao
Efficient Quantum Algorithms for Simulating Lindblad Evolution
Abstract
We consider the natural generalization of the Schrodinger equation to Markovian open system dynamics: the socalled the Lindblad equation. We give a quantum algorithm for simulating the evolution of an nqubit system for time t within precision epsilon. If the Lindbladian consists of poly(n) operators that can each be expressed as a linear combination of poly(n) tensor products of Pauli operators then the gate cost of our algorithm is O(t polylog(t/epsilon) poly(n)). We also obtain similar bounds for the cases where the Lindbladian consists of local operators, and where the Lindbladian consists of sparse operators. This is remarkable in light of evidence that we provide indicating that the above efficiency is impossible to attain by first expressing Lindblad evolution as Schrodinger evolution on a larger system and tracing out the ancillary system: the cost of such a reduction incurs an efficiency overhead of O(t^2/epsilon) even before the Hamiltonian evolution simulation begins. Instead, the approach of our algorithm is to use a novel variation of the "linear combinations of unitaries" construction that pertains to channels.
BibTeX  Entry
@InProceedings{cleve_et_al:LIPIcs:2017:7477,
author = {Richard Cleve and Chunhao Wang},
title = {{Efficient Quantum Algorithms for Simulating Lindblad Evolution}},
booktitle = {44th International Colloquium on Automata, Languages, and Programming (ICALP 2017)},
pages = {17:117:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {9783959770415},
ISSN = {18688969},
year = {2017},
volume = {80},
editor = {Ioannis Chatzigiannakis and Piotr Indyk and Fabian Kuhn and Anca Muscholl},
publisher = {Schloss DagstuhlLeibnizZentrum fuer Informatik},
address = {Dagstuhl, Germany},
URL = {http://drops.dagstuhl.de/opus/volltexte/2017/7477},
URN = {urn:nbn:de:0030drops74776},
doi = {10.4230/LIPIcs.ICALP.2017.17},
annote = {Keywords: quantum algorithms, open quantum systems, Lindblad simulation}
}
2017
Keywords: 

quantum algorithms, open quantum systems, Lindblad simulation 
Seminar: 

44th International Colloquium on Automata, Languages, and Programming (ICALP 2017)

Issue date: 

2017 
Date of publication: 

2017 