Praveen Sriram
Ph.D. Student in Applied Physics, admitted Autumn 2019
All Publications
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Clean quantum point contacts in an InAs quantum well grown on a lattice-mismatched InP substrate
PHYSICAL REVIEW B
2022; 105 (19)
View details for DOI 10.1103/PhysRevB.105.195303
View details for Web of Science ID 000804737800007
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Role of dephasing on the conductance signatures of Majorana zero modes.
Journal of physics. Condensed matter : an Institute of Physics journal
2021
Abstract
Conductance signatures that signal the presence of Majorana zero modes in a three terminal nanowire-topological superconductor hybrid system are analyzed in detail, in both the clean nanowire limit and in the presence of non-coherent dephasing interactions. In the coherent transport regime for a clean wire, we point out contributions of the local Andreev reflection and the non-local transmissions toward the total conductance lineshapes while clarifying the role of contact broadening on the Majorana conductance lineshapes at the magnetic field parity crossings. Interestingly, at larger B-field parity crossings, the contribution of the Andreev reflection process decreases which is compensated by the non-local processes in order to maintain the conductance quantum regardless of contact coupling strength. In the non-coherent transport regime, we include dephasing that is introduced by momentum randomization processes, that allows one to smoothly transition to the diffusive limit. Here, as expected, we note that while the Majorana character of the zero modes is unchanged, there is a reduction in the conductance peak magnitude that scales with the strength of the impurity scattering potentials. Dephasing due to fluctuating impurities is shown to affect the conductance lineshapes in ways that are distinguishable from the effects of contact-induced tunnel broadening. Most importantly our results reveal that the addition of dephasing in the set up does not lead to any notable length dependence to the conductance of the zero modes, contrary to what one would expect in a gradual transition to the diffusive limit. We believe this work paves a way for a systematic introduction of scattering processes into the realistic modeling of Majorana nanowire hybrid devices and assessing topological signatures in such systems in the presence of non-coherent scattering processes.
View details for DOI 10.1088/1361-648X/ac0d16
View details for PubMedID 34153946
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Supercurrent interference in semiconductor nanowire Josephson junctions
PHYSICAL REVIEW B
2019; 100 (15)
View details for DOI 10.1103/PhysRevB.100.155431
View details for Web of Science ID 000492968000008
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Bayesian view of single-qubit clocks, and an energy versus accuracy tradeoff
PHYSICAL REVIEW A
2017; 96 (3)
View details for DOI 10.1103/PhysRevA.96.032339
View details for Web of Science ID 000411973900004
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A Bayesian view of Single-Qubit Clocks, and an Energy versus Accuracy tradeoff
IEEE. 2016: 2239–43
View details for Web of Science ID 000390098702061