Anisotropic qubit-photon interactions inducing multiple antibunching-to-bunching transitions of photons.

We investigate photon correlations in the open anisotropic quantum Rabi model via quantum dressed master equation. Multiple antibunching-to-bunching transitions are generally exhibited at deep-strong qubit-photon coupling, which becomes vanishing in the standard open quantum Rabi model. The observed two-photon statistics can be well described analytically within a few lowest eigenstates at low temperatures.

Superconducting diode effect via conformal-mapped nanoholes.

A superconducting diode is an electronic device that conducts supercurrent and exhibits zero resistance primarily for one direction of applied current. Such a dissipationless diode is a desirable unit for constructing electronic circuits with ultralow power consumption. However, realizing a superconducting diode is fundamentally and technologically challenging, as it usually requires a material structure without a centre of inversion, which is scarce among superconducting materials.

Separation of nanoparticles via surfing on chemical wavefronts.

The separation of micro and nanoscale colloids is a necessary step in most biological microassay techniques, and is a common practice in microchemical processing. Chemical waves are frequently encountered in biochemical systems driven far from equilibrium. Here, we put forward a strategy for separating small suspending colloids by means of their surfing on substrate chemical wavefronts.

The mixed quantum Rabi model.

The analytical exact solutions to the mixed quantum Rabi model (QRM) including both one- and two-photon terms are found by using Bogoliubov operators. Transcendental functions in terms of 4 × 4 determinants responsible for the exact solutions are derived. These so-called G-functions with pole structures can be reduced to the previous ones in the unmixed QRMs.

Entanglement dynamics of two qubits coupled individually to Ohmic baths.

Developed originally for the Holstein polaron, the Davydov D1 ansatz is an efficient, yet extremely accurate trial state for time-dependent variation of the spin-boson model [N. Wu, L. Duan, X.

Testing a model with an extended O(2) symmetry in two and three dimensions.

We investigate a model with an extended O(2) symmetry in two and three dimensions, using the combination of extensive Monte Carlo simulations and the finite-size scaling. On this basis, we establish rich phase diagrams, which are constituted by O(2) critical lines. From various prospectives, the ordered states on the phase diagrams can be classified into intraspecies and interspecies correlated phases, quasi-long-range and long-range ordered phases, or ferromagnetic and antiferromagnetic phases.

Worm-type Monte Carlo simulation of the Ashkin-Teller model on the triangular lattice.

We investigate the symmetric Ashkin-Teller (AT) model on the triangular lattice in the antiferromagnetic two-spin coupling region (J<0). In the J→-∞ limit, we map the AT model onto a fully packed loop-dimer model on the honeycomb lattice. On the basis of this exact transformation and the low-temperature expansion, we formulate a variant of worm-type algorithms for the AT model, which significantly suppress the critical slowing down.

[Vertical transporting risk of nitrogen in purple soil affected by surfactant].

The simulated leaching experiment was conducted to determine the effects of surfactant of sodium dodecyl benzene sulphonate (SDBS) on vertical transporting of nitrogen in purple soil. SDBS could reduce NH4+ -N loss from soil, and the higher concentration of SDBS, the less loss. SDBS could increase NO3- -N loss from soil, and the order of accumulation loss is SDBS100 > SDBS40 > SDBS0 > SDBS5.

Transport and its enhancement caused by coupling.

Using the Weiss mean-field approximation theory and the particles' transport theory for the spatially periodic stochastic systems, we derive an exact analytical expression for the stationary probability current of a coupled lattice system driven by dichotomous noise. It is shown that, for this coupled lattice system, the spatial asymmetry of the system, the asymmetry of the dichotomous noise, and the coupling among nearest neighbors are the ingredients for the stationary probability current. By applying our theory to two special models, we find that (1) the coupling can lead to the directional transport of the particles (even when the potential and the dichotomous noise are symmetric) and (2) the coupling among nearest neighbors can enhance the transport of the particles in some circumstances.

Membrane-mediated interactions between nanoparticles on a substrate.

Investigations of the interactions between nanoparticles and lipid bilayer may yield insight into the understanding of the protein-biomembrane interactions and the cytotoxicity of drugs. Here, we theoretically investigate the membrane-mediated interactions between two nanoparticles supported on a substrate. We examine the effects of the packing density of lipids, the direct nanoparticle-lipid interaction, and the direct substrate-lipid interaction on the effective interactions between the nanoparticles and find the effective interactions between the two nanoparticles are mainly dominated by the competition of the deformations of the different parts of the lipid bilayers as well as the stretching of the lipid chains sandwiched between the nanoparticles.

Ground-state properties of the two-site Hubbard-Holstein model: an exact solution.

We study the two-site Hubbard-Holstein model by using an extended phonon coherent state. For the nontrivial singlet bipolarons, the double occupancy probability, the fidelity and the entanglement entropy are calculated to characterize the ground-state properties in both two-site and single-site bipolaron-dominated regimes. We use the localized minimum of the fidelity to define a crossover and plot the bipolaron phase diagram, which separates the large and small entanglement region.

Bipolaron in different configuration of quantum confinement.

The authors used Landau-Pekar variational method to investigate a strong-coupling singlet optical bipolaron in different configuration of quantum confinement. Numerical and analytical results showed that when configuration changes from quantum dot and wire to well, confinement shows different effect on the formation of a bipolaron. In contrast to a bipolaron in a quantum dot or wire, the binding energy of a bipolaron in a quantum well increases with increasing confinement, indicating that confinement favors bipolaron formation in a quantum well.

Nonequilibrium phase transitions of vortex matter in three-dimensional layered superconductors.

Large-scale simulations on the three-dimensional (3D) frustrated anisotropic XY model have been performed to study the nonequilibrium phase transitions of vortex matter in weak random pinning potential in layered superconductors. The first-order phase transition from the moving Bragg glass to the moving smectic is clarified, based on thermodynamic quantities. A washboard noise is observed in the moving Bragg glass in 3D simulations for the first time.