01527nas a2200181 4500008004100000245006900041210006900110260001500179300001100194490000700205520098100212100002001193700002401213700002301237700002201260700002501282856003801307 2015 eng d00aBilayer fractional quantum Hall states with ultracold dysprosium0 aBilayer fractional quantum Hall states with ultracold dysprosium c2015/09/10 a0336090 v923 a 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.
1 aYao, Norman, Y.1 aBennett, Steven, D.1 aLaumann, Chris, R.1 aLev, Benjamin, L.1 aGorshkov, Alexey, V. uhttp://arxiv.org/abs/1505.03099v101262nas a2200193 4500008004100000245009300041210006900134260001400203490000700217520064800224100002200872700002000894700002500914700002000939700002400959700002100983700002701004856003701031 2013 eng d00aControllable quantum spin glasses with magnetic impurities embedded in quantum solids
0 aControllable quantum spin glasses with magnetic impurities embed c2013/7/240 v883 a 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.
1 aLemeshko, Mikhail1 aYao, Norman, Y.1 aGorshkov, Alexey, V.1 aWeimer, Hendrik1 aBennett, Steven, D.1 aMomose, Takamasa1 aGopalakrishnan, Sarang uhttp://arxiv.org/abs/1307.1130v101995nas a2200205 4500008004100000245005100041210005100092260001300143490000700156520142000163100002001583700001901603700002301622700002401645700001801669700002301687700001701710700002501727856003701752 2013 eng d00aQuantum Logic between Remote Quantum Registers0 aQuantum Logic between Remote Quantum Registers c2013/2/60 v873 a 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.
1 aYao, Norman, Y.1 aGong, Zhe-Xuan1 aLaumann, Chris, R.1 aBennett, Steven, D.1 aDuan, L., -M.1 aLukin, Mikhail, D.1 aJiang, Liang1 aGorshkov, Alexey, V. uhttp://arxiv.org/abs/1206.0014v101339nas a2200193 4500008004100000245005300041210005300094260001500147490000800162520078600170100002000956700002300976700002500999700002401024700001901048700001801067700002301085856003701108 2012 eng d00aTopological Flat Bands from Dipolar Spin Systems0 aTopological Flat Bands from Dipolar Spin Systems c2012/12/260 v1093 a 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.
1 aYao, Norman, Y.1 aLaumann, Chris, R.1 aGorshkov, Alexey, V.1 aBennett, Steven, D.1 aDemler, Eugene1 aZoller, Peter1 aLukin, Mikhail, D. uhttp://arxiv.org/abs/1207.4479v3