Correlation between Lanczos Method and Exact Diagonalisation Method in the Study of Highly Correlated Electrons System

The Hubbard model is an approximate model used to describe the transition between conducting and insulating systems. The Hubbard model, named after John Hubbard 1963, is the simplest model of interacting particles in lattices, with the only two tennis in the Hamiltonian; a kinetic term allowing for hopping of particles between soles of the lattice and a potential term consisting of an on sites interaction. The particles can either be fermions or bosons.

The Hubbard model is a good approximate for particles in a periodic potential at sufficiently low temperature that all the particles are in the lowest Bloch band, as long as any long-range interactions between the particles can be ignored. If interaction between particles on different sites of the lattice are included, the model is often referred to as the extended Hubbard model .The model was originally proposed to describe electrons in solids and has since been the focus of particular interest as a model for high temperature super conductivity. Read more>>>>>>>>>>>>>>>

LEO Spacecraft Charging and Discharging Induced by High Voltage Solar Arrays

Future space missions will require higher power system. To meet these requirements, either high current or high voltage systems can be used. The use of high current is undesirable for requirement of massive power distribution cables and higherresistive losses during the power transmission. Thus high voltage power generation and transmission at low currents provided by high voltage solar arrays (HVSA) is desirable. However, space crafts with HVSA tend to undergo severe spacecraft charging and discharging issues. Especially after the launch of International Space Station (ISS) such issues have attracted increasing concerns.

HVSA induced charging and discharging mainly includes two aspects: Firstly, the interaction of HVSA with space plasma causes the spacecraft to float at a high negative potential, which typically displays as normal charging events (NCEs) or rapid charging events (RCEs). Secondly, HVSA can generate discharges, mainly including primary arc (PA) and secondary arc (SA).

The HVSA induced spacecraft charging had been considered very severe during the early years of ISS operation. Read more>>>>>>>>>>>