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We theoretically investigate quantum phases and transport dynamics of ultracold atoms trapped in an optical lattice in the presence of effective multi-body interaction. When a harmonic external potential is added, several interesting phenomena are revealed, such as the broadening and the emergence of a central insulator plateau and the phase transition between superfluid and Mott insulator phase. We also study the transport of the system which runs across the superfluid—insulator transition after ramping up the lattice, and predict a slower relaxation which is attributed to the influence of the multi-body interaction on the mass transport. [ABSTRACT FROM AUTHOR]

We investigate the transport dynamics of an interacting binary Bose—Einstein condensate in an incommensurate optical lattice and predict a novel splitting of a matter wavepacket induced by disorder potential and inter-species interaction. The effect of atomic interaction on the dynamics of the mobile and localized atoms are also studied in detail. We also discuss the behavior of the balanced and inbalanced mixtures in the incommensurate optical lattice. [ABSTRACT FROM AUTHOR]

We derive the coupled nonpolynomial nonlinear Schrödinger equations for a two-component Bose—Einstein condensate in a quasi-one-dimension geometry and investigate the effects of a tightly transverse trapping on the ground state and the miscibility—immiscibility threshold. We find that the density profile of the matter wavepacket is remarkably dependent on the transverse width and the effective one-dimension nonlinear coupling strengths in miscible and immiscible regimes. [ABSTRACT FROM AUTHOR]

We report a rapid evaporative cooling method using a hybrid trap which is composed of a quadrupole magnetic trap and a one-beam optical dipole trap. It contains two kinds of evaporative coolings to reach the quantum degeneracy: initial radio-frequency (RF) enforced evaporative cooling in the quadrupole magnetic trap and further runaway evaporative cooling in the optical dipole trap. The hybrid trap does not require a very high power laser such as that in the traditional pure optical trap, but still has a deep trap depth and a large trap volume, and has better optical access than the normal magnetic trap like the quadrupole-Ioffe-configuration (QUIC) cloverleaf trap. A high trap frequency can be easily realized in the hybrid trap to enhance the elastic collision rate and shorten the evaporative cooling time. In our experiment, pure Bose--Einstein condensates (BECs) with about 1x105 atoms can be realized in 6 s evaporative cooling in the optical dipole trap. [ABSTRACT FROM AUTHOR]

Li(Ni0.6Co0.2Mn0.2)O2 has been surface-modified by the lithium-ion conductor Li1.4)Al0.4)Ti1.6)(PO4)3 via a facile mechanical fusion method. The annealing temperature during coating process shows a strong impact on the surface morphology and chemical composition of Li(Ni0.6Co0.2Mn0.2)O2. The 600-°C annealed material exhibits the best cyclic stability at high charging cut-off voltage of 4.5 V (versus Li /Li) with the capacity retention of 90.9% after 100 cycles, which is much higher than that of bare material (79%). Moreover, the rate capability and thermal stability are also improved by Li1.4)Al0.4)Ti1.6)(PO4)3 coating. The enhanced performance can be attributed to the improved stability of interface between Li(Ni0.6Co0.2Mn0.2)O2 and electrolyte by Li1.4)Al0.4)Ti1.6)(PO4)3 modification. The results of this work provide a possible method to design reliable cathode materials to achieve high energy density and long cycle life. [ABSTRACT FROM AUTHOR]

The total conductivity of Li-biphenyl-1,2-dimethoxyethane solution (LixBp(DME)9.65, Bp = biphenyl, DME = 1,2-dimethoxyethane, x = 0.25, 0.50, 1.00, 1.50, 2.00) is measured by impedance spectroscopy at a temperature range from 0 °C to 40 °C. The Li1.50Bp(DME)9.65 has the highest total conductivity 10.7 mS/cm. The conductivity obeys Arrhenius law with the activation energy , ). The ionic conductivity and electronic conductivity of LixBp(DME)9.65 solutions are investigated at 20 °C using the isothermal transient ionic current (ITIC) technique with an ion-blocking stainless steal electrode. The ionic conductivity and electronic conductivity of Li1.00Bp(DME)9.65 are measured as 4.5 mS/cm and 6.6 mS/cm, respectively. The Li1.00Bp(DME)9.65 solution is tested as an anode material of half liquid lithium ion battery due to the coexistence of electronic conductivity and ionic conductivity. The lithium iron phosphate (LFP) and Li1.5Al0.5Ti1.5(PO4)3 (LATP) are chosen to be the counter electrode and electrolyte, respectively. The assembled cell is cycled in the voltage range of 2.2 V–3.75 V at a current density of 50 mA/g. The potential of Li1.00Bp(DME)9.65 solution is about 0.3 V vs. Li+/Li, which indicates the solution has a strong reducibility. The Li1.00Bp(DME)9.65 solution is also used to prelithiate the anode material with low first efficiency, such as hard carbon, soft carbon and silicon. [ABSTRACT FROM AUTHOR]