Confinement Tuning of Non Magnetic Fractional Quantized Conductance
ORAL
Abstract
There has been considerable interest in the possibility of fractional quantization of conductance in the absence of a magnetic field [1]. In the absence of spin-orbit coupling, appropriate systems have been modelled as 2D lattice site with a flat potential. In this work, we have investigated electron transport of a weakly confined quasi-1D quantum wire formed in a GaAs/AlGaAs heterostructure. The conductance measured almost on the verge of the 2D transition, resulted in conductance plateaux (in units of e2/h) dependent on confinement conditions. Thus flat plateau can be observed with both even and odd denominators such as 1/6, 1/2 and 2/5.. On the application of a fixed in-plane magnetic field of 10T, additional plateaux at 2/5 and 2/7 appeared as a function of increasing asymmetry in confinement potential. We suggest that the Coulomb interactions between electrons create correlated motion and formation of a zigzag array of electrons with a consequent emergence of fractional behavior [2,3].
References:
1. F.D.M. Haldane, Phys. Rev. Lett. 61, 2015 (1988).
2. Kumar et al. Phys. Rev. Lett. 122, 086803, (2019).
3. Kumar et al., Appl. Phys. Lett. 115, 123104 (2019).
References:
1. F.D.M. Haldane, Phys. Rev. Lett. 61, 2015 (1988).
2. Kumar et al. Phys. Rev. Lett. 122, 086803, (2019).
3. Kumar et al., Appl. Phys. Lett. 115, 123104 (2019).
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Presenters
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Sanjeev Kumar
University College London
Authors
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Sanjeev Kumar
University College London
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Michael Pepper
London Center for Nanotechnology, University College London
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David A Ritchie
Cavendish Laboratory, University of Cambridge, UK, Cavendish Laboratory, University of Cambridge, Cambridge University
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Ian Farrer
Department of Electronic and Electrical Engineering, University of Sheffield, UK, Department of Electronic and Electrical Engineering, University of Sheffield, University of Sheffield, Dept. of Electronic & Electrical Engineering, University of Sheffield