



01547nas a2200145   4500008004100000245006900041210006900110260001400179520108200193100001801275700002301293700002301316700002501339856003701364       2020                        eng d00aLimits on Classical Simulation of Free Fermions with Dissipation0 aLimits on Classical Simulation of Free Fermions with Dissipation  c5/21/20203 a<p>Free-fermionic systems are a valuable, but limited, class of many-body problems efficiently simulable on a classical computer. We examine how classical simulability of noninteracting fermions is modified in the presence of Markovian dissipation described by quadratic Lindblad operators, including, for example, incoherent transitions or pair losses. On the one hand, we establish three broad classes of Markovian dynamics that are efficiently simulable classically, by devising efficient algorithms. On the other hand, we demonstrate that, in the worst case, simulating Markovian dynamics with quadratic Lindblad operators is at least as hard as simulating universal quantum circuits. This result is applicable to an experimentally relevant setting in cold atomic systems, where magnetic Feshbach resonances can be used to engineer the desired dissipation. For such systems, our hardness result provides a direct scheme for dissipation-assisted quantum computing with a potential significant advantage in the speed of two-qubit gates and, therefore, in error tolerance.</p>1 aShtanko, Oles1 aDeshpande, Abhinav1 aJulienne, Paul, S.1 aGorshkov, Alexey, V.  uhttps://arxiv.org/abs/2005.10840