%0 Journal Article
%J Physical Review A
%D 2015
%T Bilayer fractional quantum Hall states with ultracold dysprosium
%A Norman Y. Yao
%A Steven D. Bennett
%A Chris R. Laumann
%A Benjamin L. Lev
%A Alexey V. Gorshkov
%X We show how dipolar interactions between dysprosium atoms in an optical lattice can be used to obtain fractional quantum Hall states. In our approach, dysprosium atoms are trapped one atom per site in a deep optical lattice with negligible tunneling. Microwave and spatially dependent optical dressing fields are used to define an effective spin-1/2 or spin-1 degree of freedom in each atom. Thinking of spin-1/2 particles as hardcore bosons, dipole-dipole interactions give rise to boson hopping, topological flat bands with Chern number 1, and the \nu = 1/2 Laughlin state. Thinking of spin-1 particles as two-component hardcore bosons, dipole-dipole interactions again give rise to boson hopping, topological flat bands with Chern number 2, and the bilayer Halperin (2,2,1) state. By adjusting the optical fields, we find a phase diagram, in which the (2,2,1) state competes with superfluidity. Generalizations to solid-state magnetic dipoles are discussed.
%B Physical Review A
%V 92
%P 033609
%8 2015/09/10
%G eng
%U http://arxiv.org/abs/1505.03099v1
%N 3
%! Phys. Rev. A
%R 10.1103/PhysRevA.92.033609
%0 Journal Article
%J Physical Review B
%D 2013
%T Controllable quantum spin glasses with magnetic impurities embedded in quantum solids
%A Mikhail Lemeshko
%A Norman Y. Yao
%A Alexey V. Gorshkov
%A Hendrik Weimer
%A Steven D. Bennett
%A Takamasa Momose
%A Sarang Gopalakrishnan
%X Magnetic impurities embedded in inert solids can exhibit long coherence times and interact with one another via their intrinsic anisotropic dipolar interaction. We argue that, as a consequence of these properties, disordered ensembles of magnetic impurities provide an effective platform for realizing a controllable, tunable version of the dipolar quantum spin glass seen in LiHo$_x$Y$_{1-x}$F$_4$. Specifically, we propose and analyze a system composed of dysprosium atoms embedded in solid helium. We describe the phase diagram of the system and discuss the realizability and detectability of the quantum spin glass and antiglass phases.
%B Physical Review B
%V 88
%8 2013/7/24
%G eng
%U http://arxiv.org/abs/1307.1130v1
%N 1
%! Phys. Rev. B
%R 10.1103/PhysRevB.88.014426
%0 Journal Article
%J Physical Review A
%D 2013
%T Quantum Logic between Remote Quantum Registers
%A Norman Y. Yao
%A Zhe-Xuan Gong
%A Chris R. Laumann
%A Steven D. Bennett
%A L. -M. Duan
%A Mikhail D. Lukin
%A Liang Jiang
%A Alexey V. Gorshkov
%X We analyze two approaches to quantum state transfer in solid-state spin systems. First, we consider unpolarized spin-chains and extend previous analysis to various experimentally relevant imperfections, including quenched disorder, dynamical decoherence, and uncompensated long range coupling. In finite-length chains, the interplay between disorder-induced localization and decoherence yields a natural optimal channel fidelity, which we calculate. Long-range dipolar couplings induce a finite intrinsic lifetime for the mediating eigenmode; extensive numerical simulations of dipolar chains of lengths up to L=12 show remarkably high fidelity despite these decay processes. We further consider the extension of the protocol to bosonic systems of coupled oscillators. Second, we introduce a quantum mirror based architecture for universal quantum computing which exploits all of the spins in the system as potential qubits. While this dramatically increases the number of qubits available, the composite operations required to manipulate "dark" spin qubits significantly raise the error threshold for robust operation. Finally, as an example, we demonstrate that eigenmode-mediated state transfer can enable robust long-range logic between spatially separated Nitrogen-Vacancy registers in diamond; numerical simulations confirm that high fidelity gates are achievable even in the presence of moderate disorder.
%B Physical Review A
%V 87
%8 2013/2/6
%G eng
%U http://arxiv.org/abs/1206.0014v1
%N 2
%! Phys. Rev. A
%R 10.1103/PhysRevA.87.022306
%0 Journal Article
%J Physical Review Letters
%D 2012
%T Topological Flat Bands from Dipolar Spin Systems
%A Norman Y. Yao
%A Chris R. Laumann
%A Alexey V. Gorshkov
%A Steven D. Bennett
%A Eugene Demler
%A Peter Zoller
%A Mikhail D. Lukin
%X 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.
%B Physical Review Letters
%V 109
%8 2012/12/26
%G eng
%U http://arxiv.org/abs/1207.4479v3
%N 26
%! Phys. Rev. Lett.
%R 10.1103/PhysRevLett.109.266804