Quantum interference of charge-density waves: Evidence for topological crystals of TaS3

We investigated Aharonov-Bohm (AB) oscillations from charge-density waves (CDWs) in TaS3 ring crystals and demonstrated that only sliding CDWs behave as a macroscopic quantum plane wave coupled to magnetic fields. The periodicity of the oscillations is h/2e within 10% accuracy. This means that sliding CDWs carry 2e charge quanta and that cannot be explained by quasi-particle interference. This is the first unambiguous experimental evidence for the AB effect in CDW loops. (C) 2008 Elsevier B.V. All rights reserved.