TY - JOUR T1 - Quantum Simulators: Architectures and Opportunities Y1 - 2019 A1 - Ehud Altman A1 - Kenneth R. Brown A1 - Giuseppe Carleo A1 - Lincoln D. Carr A1 - Eugene Demler A1 - Cheng Chin A1 - Brian DeMarco A1 - Sophia E. Economou A1 - Mark A. Eriksson A1 - Kai-Mei C. Fu A1 - Markus Greiner A1 - Kaden R. A. Hazzard A1 - Randall G. Hulet A1 - Alicia J. Kollár A1 - Benjamin L. Lev A1 - Mikhail D. Lukin A1 - Ruichao Ma A1 - Xiao Mi A1 - Shashank Misra A1 - Christopher Monroe A1 - Kater Murch A1 - Zaira Nazario A1 - Kang-Kuen Ni A1 - Andrew C. Potter A1 - Pedram Roushan AB -

Quantum simulators are a promising technology on the spectrum of quantum devices from specialized quantum experiments to universal quantum computers. These quantum devices utilize entanglement and many-particle behaviors to explore and solve hard scientific, engineering, and computational problems. Rapid development over the last two decades has produced more than 300 quantum simulators in operation worldwide using a wide variety of experimental platforms. Recent advances in several physical architectures promise a golden age of quantum simulators ranging from highly optimized special purpose simulators to flexible programmable devices. These developments have enabled a convergence of ideas drawn from fundamental physics, computer science, and device engineering. They have strong potential to address problems of societal importance, ranging from understanding vital chemical processes, to enabling the design of new materials with enhanced performance, to solving complex computational problems. It is the position of the community, as represented by participants of the NSF workshop on "Programmable Quantum Simulators," that investment in a national quantum simulator program is a high priority in order to accelerate the progress in this field and to result in the first practical applications of quantum machines. Such a program should address two areas of emphasis: (1) support for creating quantum simulator prototypes usable by the broader scientific community, complementary to the present universal quantum computer effort in industry; and (2) support for fundamental research carried out by a blend of multi-investigator, multi-disciplinary collaborations with resources for quantum simulator software, hardware, and education. 

UR - https://arxiv.org/abs/1912.06938 ER - TY - JOUR T1 - Topological Flat Bands from Dipolar Spin Systems JF - Physical Review Letters Y1 - 2012 A1 - Norman Y. Yao A1 - Chris R. Laumann A1 - Alexey V. Gorshkov A1 - Steven D. Bennett A1 - Eugene Demler A1 - Peter Zoller A1 - Mikhail D. Lukin AB - We propose and analyze a physical system that naturally admits two-dimensional topological nearly flat bands. Our approach utilizes an array of three-level dipoles (effective S = 1 spins) driven by inhomogeneous electromagnetic fields. The dipolar interactions produce arbitrary uniform background gauge fields for an effective collection of conserved hardcore bosons, namely, the dressed spin-flips. These gauge fields result in topological band structures, whose bandgap can be larger than the corresponding bandwidth. Exact diagonalization of the full interacting Hamiltonian at half-filling reveals the existence of superfluid, crystalline, and supersolid phases. An experimental realization using either ultra-cold polar molecules or spins in the solid state is considered. VL - 109 UR - http://arxiv.org/abs/1207.4479v3 CP - 26 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.109.266804 ER - TY - JOUR T1 - Quantum Magnetism with Polar Alkali Dimers JF - Physical Review A Y1 - 2011 A1 - Alexey V. Gorshkov A1 - Salvatore R. Manmana A1 - Gang Chen A1 - Eugene Demler A1 - Mikhail D. Lukin A1 - Ana Maria Rey AB - We show that dipolar interactions between ultracold polar alkali dimers in optical lattices can be used to realize a highly tunable generalization of the t-J model, which we refer to as the t-J-V-W model. The model features long-range spin-spin interactions J_z and J_perp of XXZ type, long-range density-density interaction V, and long-range density-spin interaction W, all of which can be controlled in both magnitude and sign independently of each other and of the tunneling t. The "spin" is encoded in the rotational degree of freedom of the molecules, while the interactions are controlled by applied static electric and continuous-wave microwave fields. Furthermore, we show that nuclear spins of the molecules can be used to implement an additional (orbital) degree of freedom that is coupled to the original rotational degree of freedom in a tunable way. The presented system is expected to exhibit exotic physics and to provide insights into strongly correlated phenomena in condensed matter systems. Realistic experimental imperfections are discussed. VL - 84 UR - http://arxiv.org/abs/1106.1655v1 CP - 3 J1 - Phys. Rev. A U5 - 10.1103/PhysRevA.84.033619 ER - TY - JOUR T1 - Tunable Superfluidity and Quantum Magnetism with Ultracold Polar Molecules JF - Physical Review Letters Y1 - 2011 A1 - Alexey V. Gorshkov A1 - Salvatore R. Manmana A1 - Gang Chen A1 - Jun Ye A1 - Eugene Demler A1 - Mikhail D. Lukin A1 - Ana Maria Rey AB - By selecting two dressed rotational states of ultracold polar molecules in an optical lattice, we obtain a highly tunable generalization of the t-J model, which we refer to as the t-J-V-W model. In addition to XXZ spin exchange, the model features density-density interactions and novel density-spin interactions; all interactions are dipolar. We show that full control of all interaction parameters in both magnitude and sign can be achieved independently of each other and of the tunneling. As a first step towards demonstrating the potential of the system, we apply the density matrix renormalization group method (DMRG) to obtain the 1D phase diagram of the simplest experimentally realizable case. Specifically, we show that the tunability and the long-range nature of the interactions in the t-J-V-W model enable enhanced superfluidity. Finally, we show that Bloch oscillations in a tilted lattice can be used to probe the phase diagram experimentally. VL - 107 UR - http://arxiv.org/abs/1106.1644v1 CP - 11 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.107.115301 ER - TY - JOUR T1 - Adiabatic preparation of many-body states in optical lattices JF - Physical Review A Y1 - 2010 A1 - Anders S. Sorensen A1 - Ehud Altman A1 - Michael Gullans A1 - J. V. Porto A1 - Mikhail D. Lukin A1 - Eugene Demler AB - We analyze a technique for the preparation of low entropy many body states of atoms in optical lattices based on adiabatic passage. In particular, we show that this method allows preparation of strongly correlated states as stable highest energy states of Hamiltonians that have trivial ground states. As an example, we analyze the generation of antiferromagnetically ordered states by adiabatic change of a staggered field acting on the spins of bosonic atoms with ferromagnetic interactions. VL - 81 UR - http://arxiv.org/abs/0906.2567v3 CP - 6 J1 - Phys. Rev. A U5 - 10.1103/PhysRevA.81.061603 ER - TY - JOUR T1 - Photonic Phase Gate via an Exchange of Fermionic Spin Waves in a Spin Chain JF - Physical Review Letters Y1 - 2010 A1 - Alexey V. Gorshkov A1 - Johannes Otterbach A1 - Eugene Demler A1 - Michael Fleischhauer A1 - Mikhail D. Lukin AB - We propose a new protocol for implementing the two-qubit photonic phase gate. In our approach, the pi phase is acquired by mapping two single photons into atomic excitations with fermionic character and exchanging their positions. The fermionic excitations are realized as spin waves in a spin chain, while photon storage techniques provide the interface between the photons and the spin waves. Possible imperfections and experimental systems suitable for implementing the gate are discussed. VL - 105 UR - http://arxiv.org/abs/1001.0968v3 CP - 6 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.105.060502 ER - TY - JOUR T1 - Anyonic interferometry and protected memories in atomic spin lattices JF - Nature Physics Y1 - 2008 A1 - Liang Jiang A1 - Gavin K. Brennen A1 - Alexey V. Gorshkov A1 - Klemens Hammerer A1 - Mohammad Hafezi A1 - Eugene Demler A1 - Mikhail D. Lukin A1 - Peter Zoller AB - Strongly correlated quantum systems can exhibit exotic behavior called topological order which is characterized by non-local correlations that depend on the system topology. Such systems can exhibit remarkable phenomena such as quasi-particles with anyonic statistics and have been proposed as candidates for naturally fault-tolerant quantum computation. Despite these remarkable properties, anyons have never been observed in nature directly. Here we describe how to unambiguously detect and characterize such states in recently proposed spin lattice realizations using ultra-cold atoms or molecules trapped in an optical lattice. We propose an experimentally feasible technique to access non-local degrees of freedom by performing global operations on trapped spins mediated by an optical cavity mode. We show how to reliably read and write topologically protected quantum memory using an atomic or photonic qubit. Furthermore, our technique can be used to probe statistics and dynamics of anyonic excitations. VL - 4 U4 - 482 - 488 UR - http://arxiv.org/abs/0711.1365v1 CP - 6 J1 - Nat Phys U5 - 10.1038/nphys943 ER -