



01333nas a2200157   4500008004100000245008800041210006900129260001400198520082100212100001901033700002301052700002001075700001801095700002501113856003701138       2020                        eng d00aOptimal state transfer and entanglement generation in power-law interacting systems0 aOptimal state transfer and entanglement generation in powerlaw i  c10/6/20203 a<p>We present an optimal protocol for encoding an unknown qubit state into a multiqubit Greenberger-Horne-Zeilinger-like state and, consequently, transferring quantum information in large systems exhibiting power-law (1/rα) interactions. For all power-law exponents α between d and 2d+1, where d is the dimension of the system, the protocol yields a polynomial speedup for α&gt;2d and a superpolynomial speedup for α&le;2d, compared to the state of the art. For all α&gt;d, the protocol saturates the Lieb-Robinson bounds (up to subpolynomial corrections), thereby establishing the optimality of the protocol and the tightness of the bounds in this regime. The protocol has a wide range of applications, including in quantum sensing, quantum computing, and preparation of topologically ordered states.&nbsp;</p>1 aTran, Minh, C.1 aDeshpande, Abhinav1 aGuo, Andrew, Y.1 aLucas, Andrew1 aGorshkov, Alexey, V.  uhttps://arxiv.org/abs/2010.02930