Incipient formation of an electron lattice in a weakly confined quantum wire

We study the low-temperature transport properties of 1D quantum wires as the confinement strength V_{conf} and the carrier density n_{1D} are varied using a combination of split gates and a top gate in GaAs/AlGaAs heterostructures. At intermediate V_{conf} and n_{1D}, we observe a jump in conductance to 4e;{2}/h, suggesting a double wire. On further reducing n_{1D}, plateau at 2e;{2}/h returns. Our results show beginnings of the formation of an electron lattice in an interacting quasi-1D quantum wire. In the presence of an in-plane magnetic field, mixing of spin-aligned levels of the two wires gives rise to more complex states.