Phase-locked charge-density waves in NbSe3

Abstract
Using a simple Ginzburg-Landau theory which incorporates the crystal symmetry of NbSe3, we show that the approximate relation, 2(k1+k2)(1, 1, 1), between the two charge-density-wave (CDW) wave vectors leads to a fourth-order phase locking of the CDW's. Some experimental consequences of this effect are discussed.