KIAS workshop "From correlated electrons to nanoscale materials"

at Korea Institute for Advanced Study (KIAS), Seoul, Korea

• Mahn-Soo Choi
  
  Korea University
  
  

  Title

  Strong-Coupled Spin-Boson Models and the Manipulation of Squeezing

  Abstract

  We examine several physical systems described by strongly coupled spins and bosons, and study the squeezed states of bosonic degrees of freedom. We show that the model exhibits a crossover analogous to the second-order phase transition and the squeezed state manifests itself as a precursor of the crossover. It is suggested that the squeezing of the phonon modes is associated the enhanced super-current in superconducting molecular transistors with strong electron-phonon interaction and can be manipulated by means of continuous quantum measurement of the charge on the molecule. Similar abnormal effects (but with specific visible phenomena being different) can be observed in other systems such as superconducting circuit QED.