Abstract
As a canonical response to the applied magnetic field, the electronic states of a metal are fundamentally reorganized into Landau levels. In Dirac metals, Landau levels can be expected without magnetic fields, provided that an inhomogeneous strain is applied to spatially modulate electron hoppings in a way similar to the Aharonov-Bohm phase. We here predict that a twisted zigzag nanoribbon of graphene exhibits strain-induced pseudo Landau levels of unexplored but analytically solvable dispersions at low energies. The presence of such dispersive pseudo Landau levels results in a negative strain resistivity characterizing the ($1+1$)-dimensional chiral anomaly if partially filled and can greatly enhance the thermopower when fully filled.
Highlights
A magnetic field applied to a metal can quantize the orbital motion of electrons and populate them on discrete energy bands known as the Landau levels (LLs) [1], which are responsible for a number of transport properties
In recently discovered topological semimetals [5,6,7,8,9,10], the presence of LLs accounts for the nonconservation of chiral charge transport, i.e., the chiral anomaly [11,12,13], which is observable through a negative longitudinal magnetoresistivity [14,15,16,17,18,19,20] resulting from the chiral magnetic effect [18,19,20,21]
Such an effect is analogous to the negative magnetoresistivity [14,15,16,17,18,19,20] in topological semimetals with only chiral LLs partially filled and may serve as a manifestation of the (1 + 1)-dimensional chiral anomaly [13], which coincides with the valley anomaly in graphene [82]
Summary
A magnetic field applied to a metal can quantize the orbital motion of electrons and populate them on discrete energy bands known as the Landau levels (LLs) [1], which are responsible for a number of transport properties. Anomalies [42,43], and Hall-like effects [44,45,46,47], similar to those in the context of the regular magnetotransport Such strain-induced pseudo Landau levels (pLLs) have been experimentally observed by scanning tunneling spectroscopy (STS) in nanobubbles [48,49] and nanoripples [50,51] of graphene and directly imaged by angle-resolved photoemission spectroscopy (ARPES) in wafer-scale epitaxially grown graphene on a silicon carbide (SiC) substrate with nanoprisms [52].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have