4 research outputs found
Autonomous distribution of programmable multi-qubit entanglement in a dual-rail quantum network
We propose and analyze a scalable and fully autonomous scheme for preparing
spatially distributed multi-qubit entangled states in a dual-rail waveguide QED
setup. In this approach, arrays of qubits located along two separated
waveguides are illuminated by correlated photons from the output of a
non-degenerate parametric amplifier. These photons drive the qubits into
different classes of pure entangled steady states, for which the degree of
multipartite entanglement can be conveniently adjusted by the chosen pattern of
local qubit-photon detunings. Numerical simulations for moderate-sized networks
show that the preparation time for these complex multi-qubit states increases
at most linearly with the system size and that one may benefit from an
additional speedup in the limit of a large amplifier bandwidth. Therefore, this
scheme offers an intriguing new route for distributing ready-to-use
multipartite entangled states across large quantum networks, without requiring
any precise pulse control and relying on a single Gaussian entanglement source
only.Comment: Main: 7 pages and 4 figures; Supplementary material: 6 pages and 2
figure
The bosonic skin effect: boundary condensation in asymmetric transport
We study the incoherent transport of bosonic particles through a one dimensional lattice with different left and right hopping rates, as modelled by the asymmetric simple inclusion process (ASIP). Specically, we show that as the current passing through this system increases, a transition occurs, which is signied by the appearance of a characteristic zigzag pattern in the stationary density profile near the boundary. In this highly unusual transport phase, the local particle distribution alternates on every site between a thermal state and a bose-condensed distribution with broken U (1)-symmetry. We further show that the onset of this phase is closely related to the so-called non-Hermitian skin effect and coincides with an exceptional point in the spectrum of density fluctuations. Therefore, this effect establishes an interesting connection between quantum transport, non-equilibrium condensation phenomena and non-Hermitian topology, which can be probed in cold-atom experiments or in systems with long-lived photonic, polaritonic or plasmonic excitations
The bosonic skin effect: Boundary condensation in asymmetric transport
We study the incoherent transport of bosonic particles through a one dimensional lattice with different left and right hopping rates, as modelled by the asymmetric simple inclusion process (ASIP). Specifically, we show that as the current passing through this system increases, a transition occurs, which is signified by the appearance of a characteristic zigzag pattern in the stationary density profile near the boundary. In this highly unusual transport phase, the local particle distribution alternates on every site between a thermal distribution and a Bose-condensed state with broken -symmetry. Furthermore, we show that the onset of this phase is closely related to the so-called non-Hermitian skin effect and coincides with an exceptional point in the spectrum of density fluctuations. Therefore, this effect establishes a direct connection between quantum transport, non-equilibrium condensation phenomena and non-Hermitian topology, which can be probed in cold-atom experiments or in systems with long-lived photonic, polaritonic and plasmonic excitations
Entangling microwaves and telecom wavelength light
We entangled microwave and optical photons for the first time as verified by a measured two-mode vacuum squeezing of 0.7 dB. This electro-optic entanglement is the key resource needed to connect cryogenic quantum circuits