Work on a quantum dipole by a single-photon pulse

Area of Science:

• Quantum Optics
• Quantum Thermodynamics
• Solid-State Physics

Background:

• Conventional understanding of light-matter interaction involves photon absorption and emission.
• The role of quantized fields in energy transfer to quantum systems requires further exploration.
• Quantum thermodynamics provides a framework to analyze energy exchange at the quantum level.

Purpose of the Study:

• To investigate energy transfer mechanisms from a quantized field to a quantized dipole.
• To explore novel energy transfer processes beyond standard absorption and emission.
• To characterize these processes using quantum thermodynamics, identifying them as generalized work and heat.

Main Methods:

• Theoretical investigation of energy transfer between a single photon and a two-level dipole.
• Application of quantum thermodynamical principles to analyze energy exchange.
• Analysis of conditions necessary for generalized work transfer, including pulse properties.

Main Results:

• A single photon can induce energy transfer via a dynamic Stark shift, a process termed generalized work.
• Two necessary conditions for this generalized work transfer were identified: off-resonance and finite pulse linewidth.
• The generalized work performed by a single-photon pulse matches the reactive work of a semiclassical pulse in the low-excitation limit.

Conclusions:

• Introduces a new paradigm of energy transfer mediated by single photons through dynamic Stark shifts.
• Establishes a quantum thermodynamical interpretation of energy transfer, distinguishing generalized work from generalized heat.
• Provides crucial insights into the conditions governing quantum work extraction from light fields.