Dephasing time in graphene due to interaction with flexural phonons.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Electronics

Background:

• Electron-electron interactions are a primary source of decoherence in graphene.
• The role of flexural phonons in electron decoherence is not fully understood.
• Standard theoretical approaches may not capture phonon-induced dephasing in certain regimes.

Purpose of the Study:

• To investigate the decoherence of electrons in graphene due to electron-flexural phonon interactions.
• To quantify the dephasing rate induced by flexural phonons across various temperatures and electron densities.
• To explore novel methods for identifying flexural phonons in graphene.

Main Methods:

• Theoretical investigation of electron-flexural phonon interaction in graphene.
• Calculation of the dephasing rate (τ_{ϕ}^{-1}) as a function of temperature (T) and electron density (n).
• Analysis of temperature dependence, including asymptotic regions and crossover behaviors.
• Evaluation of the dephasing rate's nonmonotonic dependence on electron density.

Main Results:

• Flexural phonons induce a dephasing rate comparable to electron-electron interactions.
• A significant temperature range exists where the golden rule fails to describe phonon-induced dephasing.
• The dephasing rate exhibits a crossover from T^{2} to T dependence with increasing temperature.
• The dephasing rate is a nonmonotonic function of electron density (n).

Conclusions:

• Electron-flexural phonon interaction is a significant contributor to decoherence in graphene.
• The unique temperature and density dependencies of this interaction provide a signature for identifying flexural phonons.
• Measuring weak-localization corrections in magnetoresistance can experimentally verify these findings and detect flexural phonons.