Qubit-oscillator systems in the ultrastrong-coupling regime and their potential for preparing nonclassical states

Understand

We consider a system composed of a two-level system (i.e.

• a qubit) and a harmonic oscillator in the ultrastrong-coupling regime, where the coupling strength is comparable to the qubit and oscillator energy scales.
• Special emphasis is placed on the possibility of preparing nonclassical states in this system.
• These nonclassical states include squeezed states, Schrodinger-cat states and entangled states.