01534nas a2200169 4500008004100000245006200041210005800103260001500161490000800176520102300184100002301207700002201230700002301252700002501275700002701300856003701327 2017 eng d00aA solvable family of driven-dissipative many-body systems0 asolvable family of drivendissipative manybody systems c2017/11/100 v1193 a

Exactly solvable models have played an important role in establishing the sophisticated modern understanding of equilibrium many-body physics. And conversely, the relative scarcity of solutions for non-equilibrium models greatly limits our understanding of systems away from thermal equilibrium. We study a family of nonequilibrium models, some of which can be viewed as dissipative analogues of the transverse-field Ising model, in that an effectively classical Hamiltonian is frustrated by dissipative processes that drive the system toward states that do not commute with the Hamiltonian. Surprisingly, a broad and experimentally relevant subset of these models can be solved efficiently in any number of spatial dimensions. We leverage these solutions to prove a no-go theorem on steady-state phase transitions in a many-body model that can be realized naturally with Rydberg atoms or trapped ions, and to compute the effects of decoherence on a canonical trapped-ion-based quantum computation architecture.

1 aFoss-Feig, Michael1 aYoung, Jeremy, T.1 aAlbert, Victor, V.1 aGorshkov, Alexey, V.1 aMaghrebi, Mohammad, F. uhttps://arxiv.org/abs/1703.0462609346nas a2200181 4500008004100000245005500041210005400096260001500150520881500165100001908980700001608999700002309015700002409038700002009062700002009082700002509102856003709127 2016 eng d00aSteady-state superradiance with Rydberg polaritons0 aSteadystate superradiance with Rydberg polaritons c2016/11/023 a

A steady-state superradiant laser can be used to generate ultranarrow-linewidth light, and thus has important applications in the fields of quantum information and precision metrology. However, the light produced by such a laser is still essentially classical. Here, we show that the introduction of a Rydberg medium into a cavity containing atoms with a narrow optical transition can lead to the steady-state superradiant emission of ultranarrow-linewidth nonclassical light. The cavity nonlinearity induced by the Rydberg medium strongly modifies the superradiance threshold, and leads to a Mollow triplet in the cavity output spectrumthis behavior can be understood as an unusual analogue of resonance fluorescence. The cavity output spectrum has an extremely sharp central peak, with a linewidth that can be far narrower than that of a classical superradiant laser. This unprecedented spectral sharpness, together with the nonclassical nature of the light, could lead to new applications in which spectrally pure quantum light is desired.

1 aGong, Zhe-Xuan1 aXu, Minghui1 aFoss-Feig, Michael1 aThompson, James, K.1 aRey, Ana, Maria1 aHolland, Murray1 aGorshkov, Alexey, V. uhttps://arxiv.org/abs/1611.0079702020nas a2200265 4500008004100000245009000041210006900131260001400200490000800214520123900222100001501461700001801476700002301494700002801517700001801545700002601563700001201589700002201601700002101623700002101644700001201665700002001677700002001697856003701717 2014 eng d00aSuppressing the loss of ultracold molecules via the continuous quantum Zeno effect 0 aSuppressing the loss of ultracold molecules via the continuous q c2014/2/200 v1123 a We investigate theoretically the suppression of two-body losses when the on-site loss rate is larger than all other energy scales in a lattice. This work quantitatively explains the recently observed suppression of chemical reactions between two rotational states of fermionic KRb molecules confined in one-dimensional tubes with a weak lattice along the tubes [Yan et al., Nature 501, 521-525 (2013)]. New loss rate measurements performed for different lattice parameters but under controlled initial conditions allow us to show that the loss suppression is a consequence of the combined effects of lattice confinement and the continuous quantum Zeno effect. A key finding, relevant for generic strongly reactive systems, is that while a single-band theory can qualitatively describe the data, a quantitative analysis must include multiband effects. Accounting for these effects reduces the inferred molecule filling fraction by a factor of five. A rate equation can describe much of the data, but to properly reproduce the loss dynamics with a fixed filling fraction for all lattice parameters we develop a mean-field model and benchmark it with numerically exact time-dependent density matrix renormalization group calculations. 1 aZhu, Bihui1 aGadway, Bryce1 aFoss-Feig, Michael1 aSchachenmayer, Johannes1 aWall, Michael1 aHazzard, Kaden, R. A.1 aYan, Bo1 aMoses, Steven, A.1 aCovey, Jacob, P.1 aJin, Deborah, S.1 aYe, Jun1 aHolland, Murray1 aRey, Ana, Maria uhttp://arxiv.org/abs/1310.2221v201233nas a2200157 4500008004100000245006500041210006300106260001400169490000800183520075800191100002300949700002200972700002400994700002001018856003701038 2012 eng d00aSteady-state many-body entanglement of hot reactive fermions0 aSteadystate manybody entanglement of hot reactive fermions c2012/12/40 v1093 a Entanglement is typically created via systematic intervention in the time evolution of an initially unentangled state, which can be achieved by coherent control, carefully tailored non-demolition measurements, or dissipation in the presence of properly engineered reservoirs. In this paper we show that two-component Fermi gases at ~\mu K temperatures naturally evolve, in the presence of reactive two-body collisions, into states with highly entangled (Dicke-type) spin wavefunctions. The entanglement is a steady-state property that emerges---without any intervention---from uncorrelated initial states, and could be used to improve the accuracy of spectroscopy in experiments with fermionic alkaline earth atoms or fermionic groundstate molecules. 1 aFoss-Feig, Michael1 aDaley, Andrew, J.1 aThompson, James, K.1 aRey, Ana, Maria uhttp://arxiv.org/abs/1207.4741v1