Auto- versus Cross-Correlation Noise in Periodically Driven Quantum Coherent Conductors

Area of Science:

• Quantum transport phenomena
• Mesoscopic physics
• Solid-state physics

Background:

• Understanding electrical current fluctuations is crucial in quantum electronics.
• Shot noise provides insights into the quantum nature of charge carriers.
• Existing models often lack a clear distinction between different noise contributions.

Purpose of the Study:

• To develop a novel approach for analyzing shot noise in multi-probe conductors.
• To differentiate between two distinct physical contributions to shot noise.
• To investigate the implications of this analysis for quantum transport and particle creation.

Main Methods:

• Expressing currents and fluctuations using carrier wave functions in the Fermi sea.
• Analyzing shot noise in the quantum coherent and weak back-scattering regimes.
• Decomposing shot noise into autocorrelation and cross-correlation components.

Main Results:

• Identified two distinct contributions to shot noise: autocorrelation and cross-correlation noise.
• Cross-correlation noise depends on wave packet duration in the quantum coherent regime.
• Autocorrelation noise depends on wave packet duration and coherence (energy spread).

Conclusions:

• The developed approach offers new physical insights into electric currents and shot noise.
• Shot noise analysis can distinguish between wave packet duration and coherence effects.
• Predicts that clean creation of individual Majorana fermions is not possible without electron-hole pairs.