Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 14: Symposium Quanten-Hall-Systeme

HL 14.6: Vortrag

Dienstag, 9. März 2004, 12:45–13:15, H15

Momentum resolved tunnel spectroscopy: Investigating interactions at quantum Hall edges — •Matthew Grayson und Matthew Grayson — Walter Schottky Institut, Tech. Univ. Muenchen

We present experimental results on magneto-tunneling between a single quantum Hall (QHE) edge and an orthogonal high-mobility two-dimensional contact in a T-shaped quantum well configuration. Simultaneous conservation of energy E and canonical momentum k parallel to the QHE edge allows us to directly probe the E vs. k dispersion relation of individual integer QHE edge channels with excitation energies up to 100 meV. At high voltages, screening in the QHE edge is found to significantly distort the dispersion relation in a fashion that is in excellent agreement with Hartree calculations of the real-space edge potential. At low voltages of order the Coulomb interaction energy, we find evidence for an exchange-enhanced spin splitting of the integer quantum Hall effect edge.