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Updated: May 30, 2026
07:46
Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Two-particle irreducible effective action approach to nonlinear current-conserving approximations in driven systems.
1CONICET and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón I, 1428 Buenos Aires, Argentina.
Summary
We developed a gauge-invariant effective action method to study open electronic systems. This approach ensures electronic current conservation in response to electromagnetic fields, crucial for understanding current fluctuations.
Area of Science:
- Condensed Matter Physics
- Quantum Field Theory
Background:
- Open interacting electronic systems respond to external fields.
- Calculating these responses requires advanced theoretical frameworks.
Purpose of the Study:
- To develop a systematic method for calculating response functions in open electronic systems.
- To ensure electronic current conservation in theoretical models.
Main Methods:
- Utilizing closed-time-path two-particle irreducible coarse-grained effective action (CTP 2PI CGEA) techniques.
- Applying Schwinger-Dyson and Bethe-Salpeter equations for propagator and response function calculations.
Main Results:
- Demonstrated gauge invariance of the CTP 2PI CGEA under simultaneous transformations.
- Showed that response functions satisfy the Ward-Takahashi hierarchy, ensuring current conservation.
- Clarified the link between nonlinear response theory and the Ward-Takahashi hierarchy.
Conclusions:
- The CTP 2PI CGEA provides a robust framework for studying electronic systems.
- The method guarantees electronic current conservation, essential for accurate theoretical predictions.
- Findings are applicable to understanding current fluctuations in electronic pumping devices.
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