Quantum Critical Dynamics in Two Quantum Magnets

          @misc{ scivideos_PIRSA:16110075,
            doi = {10.48660/16110075},
            url = {https://pirsa.org/16110075},
            author = {Wu, Jianda},
            keywords = {Quantum Matter},
            language = {en},
            title = {Quantum Critical Dynamics in Two Quantum Magnets},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2016},
            month = {nov},
            note = {PIRSA:16110075 see, \url{https://scivideos.org/pirsa/16110075}}
          }
          

Abstract

Quantum phase transitions arise at zero temperature when ground state energy meets non-analyticity upon tuning a non-thermal parameter.

Physical properties around quantum critical points (QCPs) are of extensive current interests because the fierce competition between critical quantum and thermal fluctuations near the QCPs can strongly affect dynamics and thermodynamics, leading to unconventional physics.

Despite of its great interests, however, it remains challenge to analytically understand such real frequency dynamics in strongly-correlated quantum systems, even for the dynamics in the quantum systems of one spatial dimension.

 

In the talk, motivated by recent experimental progresses, we shall take the challenge via analytically exploring finite temperature dynamics at the QCP of 3(space)+1(time) quantum φ^4 model, and zero-temperature spin dynamics in the quantum critical regime of XXZ Heisenberg model.

 

During the exciting excursion, sophisticated but powerful theoretical tools were introduced, and a bunch of new physics beyond conventional pictures were discovered. At the end we shall also discuss the implication of our results for experiments in relevant materials and suggest proper future experimental setups to test our theoretical findings.