Single-impurity-induced Dicke quantum phase transition in a cavity-Bose-Einstein condensate

Area of Science:

• Quantum physics
• Condensed matter physics
• Atomic physics

Background:

• The standard Dicke model describes quantum phase transitions in systems of atoms interacting with a cavity field.
• Realizing Dicke quantum phase transitions typically requires strong coupling between the cavity field and atoms.

Purpose of the Study:

• To introduce and investigate a generalized Dicke model using an impurity-doped cavity-Bose-Einstein condensate (BEC).
• To explore the potential of a single impurity atom to induce and control quantum phase transitions in a macroscopic quantum system.

Main Methods:

• Theoretical modeling of an impurity-doped Dicke model (IDDM).
• Analysis of quantum phase transitions (QPT) from normal to superradiant phases.
• Investigation of the role of impurity population and field-atom coupling regimes.

Main Results:

• The impurity atom can induce a Dicke quantum phase transition (QPT) at a critical impurity population.
• Impurity-induced Dicke QPT occurs in arbitrary field-atom coupling regimes, unlike the standard model's requirement for strong coupling.
• Demonstration of control over a macroscopic quantum system (BEC) via a microscopic quantum system (impurity atom).

Conclusions:

• The impurity-doped Dicke model provides a novel pathway to achieve quantum phase transitions.
• This work enables the control of macroscopic quantum phenomena using microscopic quantum systems.
• The findings open new possibilities for manipulating quantum properties in BECs.