Robust Nodal Structure of Landau Level Wave Functions Revealed by Fourier Transform Scanning Tunneling Spectroscopy

K. Hashimoto (1) , T. Champel (2) , Serge Florens (3) , C. Sohrmann , J. Wiebe , Y. Hirayama (1) , R. A. Roemer , R. Wiesendanger , M. Morgenstern

1 Tohoku University - Department of Physics, Tohoku University
2 LPM2C - Laboratoire de physique et modélisation des milieux condensés
3 NEEL - ThQC - Théorie Quantique des Circuits

Scanning tunneling spectroscopy is used to study the real-space local density of states (LDOS) of a two-dimensional electron system in magnetic field, in particular within higher Landau levels (LL). By Fourier transforming the LDOS, we find a set of n radial minima at fixed momenta for the nth LL. The momenta of the minima depend only on the inverse magnetic length. By comparison with analytical theory and numerical simulations, we attribute the minima to the nodes of the quantum cyclotron orbits, which decouple in Fourier representation from the random guiding center motion due to the disorder. This robustness of the nodal structure of LL wave functions should be viewed as a key property of quantum Hall states.

Domaines: Autre [cond-mat.other]

K. Hashimoto, T. Champel, Serge Florens, C. Sohrmann, J. Wiebe, et al.. Robust Nodal Structure of Landau Level Wave Functions Revealed by Fourier Transform Scanning Tunneling Spectroscopy. Physical Review Letters, 2012, 109, pp.116805. ⟨10.1103/PhysRevLett.109.116805⟩. ⟨hal-00666140⟩