We investigate a domain structure of pseudospins, a soliton lattice in the bilayer quantum Hall state at total Landau level filling factor $\nu =1$, in a tilted magnetic field, where the pseudospin represents the layer degree of freedom. An anomalous peak in the magnetoresistance $R_{xx}$ appears at the transition point between the commensurate and incommensurate phases. The $R_{xx}$ at the peak is highly anisotropic for the angle between the in-plain magnetic field $B_{\parallel }$ and the current, and indicates a formation of the soliton lattice aligned parallel to $B_{\parallel }$. The temperature dependence of the $R_{xx}$ peak reveals that the dissipation is caused by thermal fluctuations of pseudospin solitons. We also study a phase diagram of the bilayer $\nu =1$ system, and the effects of density imbalance between the two layers.

• Received 30 December 2006

DOI:https://doi.org/10.1103/PhysRevLett.100.016801