01706nas a2200193 4500008004100000245008500041210006900126260001400195490000600209520111700215100001901332700001901351700001801370700001601388700002401404700002201428700002501450856003701475 2021 eng d00aFrustration-induced anomalous transport and strong photon decay in waveguide QED0 aFrustrationinduced anomalous transport and strong photon decay i c9/16/20210 v33 a
We study the propagation of photons in a one-dimensional environment consisting of two non-interacting species of photons frustratingly coupled to a single spin-1/2. The ultrastrong frustrated coupling leads to an extreme mixing of the light and matter degrees of freedom, resulting in the disintegration of the spin and a breakdown of the "dressed-spin", or polaron, description. Using a combination of numerical and analytical methods, we show that the elastic response becomes increasingly weak at the effective spin frequency, showing instead an increasingly strong and broadband response at higher energies. We also show that the photons can decay into multiple photons of smaller energies. The total probability of these inelastic processes can be as large as the total elastic scattering rate, or half of the total scattering rate, which is as large as it can be. The frustrated spin induces strong anisotropic photon-photon interactions that are dominated by inter-species interactions. Our results are relevant to state-of-the-art circuit and cavity quantum electrodynamics experiments.
1 aBelyansky, Ron1 aWhitsitt, Seth1 aLundgren, Rex1 aWang, Yidan1 aVrajitoarea, Andrei1 aHouck, Andrew, A.1 aGorshkov, Alexey, V. uhttps://arxiv.org/abs/2007.0369002064nas a2200181 4500008004100000245007100041210006900112260001300181520150800194100001901702700001901721700001801740700001601758700002401774700002201798700002501820856003701845 2020 eng d00aTransport and dynamics in the frustrated two-bath spin-boson model0 aTransport and dynamics in the frustrated twobath spinboson model c7/7/20203 aWe study the strong coupling dynamics as well as transport properties of photons in the two-bath spin-boson model, in which a spin-1/2 particle is frustratingly coupled to two independent Ohmic bosonic baths. Using a combination of numerical and analytical methods, we show that the frustration in this model gives rise to rich physics in a very wide range of energies. This is in contrast to the one-bath spin-boson model, where the non-trivial physics occurs at an energy scale close to the renormalized spin frequency. The renormalized spin frequency in the two-bath spin-boson model is still important, featuring in different observables, including the non-equiblirum dynamics of both the spin and the baths along with the elastic transport properties of a photon. The latter however reveals a much more complex structure. The elastic scattering displays non-monotonic behavior at high frequencies, and is very different in the two channels: intra- and inter-bath scattering. The photon can also be inelastically scattered, a process in which it is split into several photons of smaller energies. We show that such inelastic processes are highly anisotropic, with the outgoing particles being preferentially emitted into only one of the baths. Moreover, the inelastic scattering rate is parameterically larger than in the one-bath case, and can even exceed the total elastic rate. Our results can be verified with state-of-the-art circuit and cavity quantum electrodynamics experiments.
1 aBelyansky, Ron1 aWhitsitt, Seth1 aLundgren, Rex1 aWang, Yidan1 aVrajitoarea, Andrei1 aHouck, Andrew, A.1 aGorshkov, Alexey, V. uhttps://arxiv.org/abs/2007.0369001878nas a2200169 4500008004100000245007200041210006900113260001500182490000800197520135800205100002801563700001801591700001601609700002501625700002201650856003601672 2019 eng d00aInteracting Qubit-Photon Bound States with Superconducting Circuits0 aInteracting QubitPhoton Bound States with Superconducting Circui c2018/01/300 vX 93 aQubits strongly coupled to a photonic crystal give rise to many exotic physical scenarios, beginning with single and multi-excitation qubit-photon dressed bound states comprising induced spatially localized photonic modes, centered around the qubits, and the qubits themselves. The localization of these states changes with qubit detuning from the band-edge, offering an avenue of in situ control of bound state interaction. Here, we present experimental results from a device with two qubits coupled to a superconducting microwave photonic crystal and realize tunable on-site and inter-bound state interactions. We observe a fourth-order two photon virtual process between bound states indicating strong coupling between the photonic crystal and qubits. Due to their localization-dependent interaction, these states offer the ability to create one-dimensional chains of bound states with tunable and potentially long-range interactions that preserve the qubits' spatial organization, a key criterion for realization of certain quantum many-body models. The widely tunable, strong and robust interactions demonstrated with this system are promising benchmarks towards realizing larger, more complex systems of bound states.
1 aSundaresan, Neereja, M.1 aLundgren, Rex1 aZhu, Guanyu1 aGorshkov, Alexey, V.1 aHouck, Andrew, A. uhttp://arxiv.org/abs/1801.10167