Quantum dot version of topological phase: half-integer orbital angular momenta
V. D. Mur, N. B. Narozhny, A. N. Petrosyan,Yu. E. Lozovik*
Moscow Engineering Physics Institute, 115409 Moscow, Russia
*Institute of Spectroscopy RAS, 142190 Troitsk, Moscow region, Russia
PACS: 02.40.-k, 03.65.Vf, 73.21.La, 75.75.+a
Abstract
We show that there exists a topological phase equal to
π for circular quantum dots with an odd number of electrons. The
non-zero value of the topological phase is explained by axial
symmetry and two-dimensionality of the system. Its particular value
(π) is fixed by the Pauli exclusion principle and leads to
half-integer values for the eigenvalues of the orbital angular
momentum. Our conclusions agree with the experimental results of T.
Schmidt et al., Phys. Rev. B 51, 5570 (1995), which can be
considered as the first experimental evidence for the existence of
the new topological phase and half-integer quantization of the
orbital angular momentum in a system of an odd number of electrons
in circular quantum dots.