Magnetoresistance of antidot lattices with grain boundaries

Abstract

The magnetotransport properties of antidot lattices containing artificially designed grain boundaries have been measured. We find that the grain boundaries broaden the commensurability resonances and displace them anisotropically. These phenomena are unexpectedly weak but differ characteristically from isotropic, Gaussian disorder in the antidot positions. The observations are interpreted in terms of semiclassical trajectories which tend to localize along the grain boundaries within certain magnetic field intervals. Furthermore, our results indicate how the transport through superlattices generated by self-organizing templates may get influenced by grain boundaries.

Small scale lateral superlattices in two-dimensional electron gases prepared by diblock copolymer masks

“…A hexagonal lattice containing grain boundaries was generated by a Monte Carlo method described elsewhere. [23] The corresponding simulated trace of ρ xx (B), see Fig. 3(a), shows a significant damping of the magnetoresistance peak, while the slope of the PMR close to B = 0 remains basically unaffected.…”

“…For this purpose, a hexagonal lattice containing grain boundaries ͑GBs͒ was generated by a Monte Carlo method as described elsewhere. 23 The corresponding simulated trace of xx ͑B͒ ͓see Fig. 3͑a͔͒ shows a significant damping of the magnetoresistance peak.…”