Spatially confined fractional quantum states in one-dimension*

Recently, the quantized conductance in asymmetrically confined quasi-one-dimensional quantum wires formed in GaAs/AlGaAs based heterostructures was shown to appear at fractional values of e²/h in the absence of a quantising magnetic field [1-3]. In this work, we show that when an electrostatically defined 1D quantum wire was spatially relaxed by shallowing the confinement potential, the interacting 1D electrons formed a zigzag resulting in fractional conductance states at 1 and 2/5. Additional fractional states appeared at 2/5 and 2/7 on applying a large in-plane magnetic field. The magnetic field, in addition to electron-electron interaction, may result in antiphase correlated motion resulting in a more complex pattern of cyclic motion [2]. Temperature dependence of 2/5 state shows the fractional state was stable until 300 mK before starting to smear out.

References:

1. Kumar et al. Phys. Rev. Lett. 122, 086803, (2019).

2. Kumar and Pepper, Appl. Phys. Lett. 119, 110502 (2021).

3. G. Shavit and Y. Oreg, Phys. Rev. Lett. 123 036803 (2019).