Xueli Luo | Searcharxiv

arXiv2021

Topological impact of a simple self-replication geometric structure with great application potential in vacuum pumping and photovoltaic industry

Topological effects exist from a macroscopic system such as the universe to a microscopic system described by quantum mechanics. We show here that an interesting geometric structure can be created by the self replication procedure of a square with an enclosed circle, in which the sum of the circles area will remain the same but the sum of the circumference will increase. It is demonstrated by means of Monte Carlo simulations that these topological features have great impacts to the vacuum pumping probability and the photon absorption probability of the active surface. The results show significant improvement of the system performance and have application potential in vacuum pumping of large research facilities such as a nuclear fusion reactor, synchrotron and in photovoltaic industry.

physics.app-ph↗

arXiv2003

Quasi-spin Model for Macroscopic Quantum Tunnelling between Two Coupled Bose-Einstein Condensates

The macroscopic quantum tunneling between two coupled Bose-Einstein condensates (BEC) (radio-frequency coupled two-component BECs or two BECs confined in a double-well potential) is mapped onto the tunneling of an uniaxial spin with an applied magnetic field. The tunneling exponent is calculated with an imaginary-time path-integral method. In the limit of low barrier, the dependence of tunneling exponent on the system parameters is obtained, and the crossover temperature from thermal regime to quantum regime is estimated. The detailed information about the tunnelling will give help to control population conversion between coupled BECs and realize quantum computation with coupled BECs.

cond-mat.mes-hall↗