Quantum Hall Response to Time-Dependent Strain Gradients in Graphene

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Mechanical deformations in graphene can be described by a Dirac Hamiltonian term analogous to an electromagnetic vector potential.
• Strain gradients in graphene generate local pseudomagnetic fields and energy gaps, which have been experimentally verified.

Purpose of the Study:

• To introduce a pseudoelectric field in graphene ribbons by applying time-dependent oscillating stress.
• To investigate the Hall-like response to combined pseudomagnetic and pseudoelectric fields.
• To predict a quantized Hall current in graphene under specific experimental conditions.

Main Methods:

• Theoretical modeling of graphene under mechanical stress.
• Analysis of the Dirac Hamiltonian with strain-induced pseudomagnetic and pseudoelectric fields.
• Investigation of the (pseudo)quantum Hall regime with weak intervalley scattering.

Main Results:

• A strain-induced charge current along the graphene ribbon is observed due to the combined fields.
• An approximately quantized Hall current is predicted.
• The predicted Hall current is robust against screening effects from diffusion currents.

Conclusions:

• Time-dependent stress can generate a pseudoelectric field in graphene, complementing existing pseudomagnetic fields.
• This approach leads to a strain-induced Hall current with potential for quantization.
• The findings offer a novel method for manipulating electronic transport in graphene.