Heat capacity of periodically driven two-level systems

Area of Science:

• Thermodynamics
• Quantum mechanics
• Statistical mechanics

Background:

• Understanding heat capacity in driven systems is crucial for nonequilibrium thermodynamics.
• Dissipative two-level systems provide a model for studying driven quantum phenomena.

Purpose of the Study:

• To define and compute heat capacity for steady periodically driven systems.
• To investigate the influence of kinetic information and driving parameters on heat capacity.

Main Methods:

• Defining heat capacity for periodically driven systems.
• Computing heat capacity for dissipative two-level systems with a time-modulated energy gap.
• Analyzing the dependence on ambient temperature, transition rates, and driving frequency/amplitude.

Main Results:

• The Schottky peak remains dominant in the heat capacity of driven two-level systems.
• Nonequilibrium heat capacity reveals kinetic information, including transition rates and kinetic barriers.
• Heat capacity vanishes at absolute zero but at a different rate compared to equilibrium systems.

Conclusions:

• The study extends the concept of heat capacity to driven systems, incorporating kinetic information.
• Nonequilibrium thermodynamics can be probed through heat capacity measurements, revealing insights into system dynamics.
• The findings have implications for understanding thermal properties in periodically driven quantum systems.