Transition from a one-dimensional to a quasi-one-dimensional state in interacting quantum wires

Vinod Ashokan, Vidit Gangwar, Gautam Shah +1 more

Mehul Dixit, Tobias Meng, Markus Garst +2 more

Julia S. Meyer, К. А. Матвеев, A. I. Larkin

Upon increasing the electron density in a quantum wire, the one-dimensional electron system undergoes a transition to a quasi-one-dimensional state. In the absence of interactions between electrons, this corresponds to filling up the second subband of transverse quantization, and there are two gapless excitation modes above the transition. On the other hand, strongly interacting one-dimensional electrons form a Wigner crystal, and the transition corresponds to it splitting into two chains (zigzag crystal). We show that the soft mode driving the transition to the zigzag state is gapped, and only one gapless mode exists above the transition. Furthermore, we establish that in the vicinity of the transition already arbitrarily weak interactions open a gap in the second mode. We then argue that only one gapless mode exists near the transition at any interaction strength.

Gang Sun, T. Vekua

By decreasing the transversal confinement potential in interacting quantum wires and populating the second energetically lowest sub-band, electron systems transition into a quasi-one-dimensional state with dominant superconducting correlations and one gapless mode. By combining effective field theory approach and numerical density matrix renormalization group simulations we show that this quasi-one-dimensional state is a topological state that hosts Majorana edge modes. We also study the single-particle correlations across the interface between this quasi-one-dimensional and single-channel states.

Amit Agarwal

Amir Yacoby