 |
||||||||||||||||||||||||||||||||
|
|
Effect of Periodic Pattern on Two Dimensional Electron SystemsIRG 1 & 2: S. Melinte, M. Berciu, C. G. Zhou, E. Tutuc, S. J. Papadakis, C. Harrison, E. P. De Poortere, M. W. Wu, P. M. Chaikin, M. Shayegan, R. N. Bhatt, and R. A. Register
By patterning gates of hexagonal symmetry using a template formed
by a diblock copolymer nanolithography technique (see below), we have discovered unexpectedly
large effects [1] in longitudinal transport of a two dimensional electron gas buried several
tens of nanometers below the surface. The strong, asymmetric broadening the conductivity peaks
for the patterned sample (right) compared to the pristine case (left) is understood as a
cooperative effect of long range (mesoscale) potential fluctuations and the weak periodic
potential [2,3]. The asymmetry is due to the triangular structure, and is not expected for a
square lattice.
References:
1. S. Melinte, M. Berciu, C. G. Zhou, E. Tutuc, S. J. Papadakis, C. Harrison, E. P. De Poortere,
M. Wu, P. M. Chaikin, M. Shayegan, R. N. Bhatt, and R. A. Register, “A Laterally Modulated 2D Electron System in the Extreme Quantum Limit,” Phys. Rev. Lett., 92, 036802 (2004).
2. C. G. Zhou and M. Berciu, “Longitudinal Conductance of Mesoscopic Hall Samples with Arbitrary Disorder and Periodic Modulations,” Phys. Rev. B, 70, 165318 (2004).
3. C. G. Zhou, M. Berciu, and R. N. Bhatt, “Effects of Large Disorder on the Hofstadter Butterfly”, Phys. Rev. B, 71, 125310 (2005).
|
||||||||||||||||||||||||||||||
|
