Mesoscopic conductors and correlations in laser speckle patterns.

Area of Science:

• Condensed matter physics
• Quantum mechanics
• Wave phenomena

Background:

• Disordered metallic systems exhibit conductance fluctuations at low temperatures due to coherent electron wave interference.
• Quantum interference leads to an counterintuitive increase in 1/f noise power as temperature decreases in disordered conductors.

Purpose of the Study:

• To investigate the phenomenon of conductance fluctuations and 1/f noise in submicrometer disordered metallic systems at low temperatures.
• To explore the applicability of theoretical techniques developed for electron transport to light transmission in random media.
• To predict novel correlations in laser speckle patterns and enable the study of scatterer dynamics.

Main Methods:

• Theoretical analysis of coherent electron wave transmission in disordered systems.
• Application of quantum interference principles to light propagation through random media.
• Development of models to predict correlations in laser speckle patterns.

Main Results:

• Observed conductance fluctuation effects driven by quantum interference.
• Demonstrated that 1/f noise power increases with decreasing temperature in disordered conductors.
• Extended theoretical framework to optical phenomena, predicting novel laser speckle correlations.

Conclusions:

• Quantum interference is a key mechanism governing electron transport and noise in disordered conductors at low temperatures.
• The theoretical approach provides a unified framework for understanding wave phenomena in both electronic and optical systems.
• Novel methods are proposed for characterizing scatterers in random media using laser speckle analysis.