High-temperature superconductors

Superconductivity is a phenomeno that electrons transport without dissipation and therefore exhibit no resistance. High-temperature superconductors have been discovered since 1986, while its machenism remains one of the biggest mistary in the condensed matter physics. The main challenging is the existance of a number of competing states with extremely close energies, which requires high accuracy in the theoritical calculations.

We have a series of important works on this topic. By utilizing the advance computational techniques, in particular tensor network and quantum Monte Carlo, we are able to obtain the ground state and the low-energy excited states with high accuracy. By studying the theoritical models we have a reliable understanding of the properties of the systems. For example, the spin and charge densities show a special pattern which is the so-called stripe state, which may consist or compete with superconductivity.

The ultimate goal is to understand the foundenmantal physics in cuprate superconductors. We try to acheive this goal by small steps. First we identify theoritical models that captures all the right physics in superconductor experiments, and then by studying these models we may learn the machenism of pairing.