Magic Angle Effects and Angular Magnetoresistance Oscillations as Dimensional Crossovers

Abstract

Interference effects between velocity and density of states, which occur as electrons move along open orbits in the extended Brillouin zone in anisotropic conductors, result in a change of wave functions' dimensionality at magic angle (MA) directions of a magnetic field. In particular, these $1\mathrm{D}\ensuremath{\rightarrow}2\mathrm{D}$ dimensional crossovers result in the appearance of sharp minima in a resistivity component ${\ensuremath{\rho}}_{\ensuremath{\perp}}(H,\ensuremath{\alpha})$, perpendicular to conducting layers. This explains the main qualitative features of MA and angular magnetoresistance oscillations' phenomena observed due to the existence of quasi-one-dimensional sheets of Fermi surface in $(\mathrm{T}\mathrm{M}\mathrm{T}\mathrm{S}\mathrm{F}{)}_{2}X$, $(\mathrm{D}\mathrm{M}\mathrm{E}\mathrm{T}\mathrm{\text{\ensuremath{-}}}\mathrm{T}\mathrm{S}\mathrm{e}\mathrm{F}{)}_{2}X$, and $\ensuremath{\kappa}\mathrm{\text{\ensuremath{-}}}(\mathrm{E}\mathrm{T}{)}_{2}\mathrm{C}\mathrm{u}(\mathrm{N}\mathrm{C}\mathrm{S}{)}_{2}$ conductors.