Hartman effect and spin precession in graphene

Abstract

Spin precession has been used to measure the transmission time τover a distance L in a graphene sheet. Since conduction electrons in graphene have an energy-independent velocity v, one would expect τ> L/v. Here we calculate that τ< L/v at the Dirac point (= charge neutrality point) in a clean graphene sheet, and we interpret this result as a manifestation of the Hartman effect (apparent superluminality) known from optics.

6 pages, 4 figures; v2: added a section on the case of perpendicularly aligned magnetizations; v3: added a figure

References in corpus (7)

• Substrate-induced band gap opening in epitaxial graphene
• Electronic spin transport and spin precession in single graphene layers at room temperature
• Substrate-induced bandgap in graphene on hexagonal boron nitride
• Quantum-limited shot noise in graphene
• Phase Coherent Transport of Charges in Graphene Quantum Billiard
• Shot Noise in Ballistic Graphene
• Shot Noise in Graphene

Cited by in corpus (10)

• The Larmor clock and anomalous spin dephasing in silicon
• Timescales of tunneling decay of a localized state
• Implications of the Klein tunneling times on high frequency graphene devices using Bohmian trajectories
• Non-Hermitian Hartman effect
• Ballistic collective group delay and its Goos-Hänchen component in graphene
• Klein tunnelling and Hartman effect in graphene junctions with proximity exchange field
• Gap-tunable of Tunneling Time in Graphene Magnetic Barrier
• Spin dynamics in tunneling decay of a metastable state
• Effect of strain on tunneling time in graphene magnetic barrier
• Average and instantaneous velocities of energy of evanescent modes