Majorana entropy revival via tunneling phases

Abstract

Measuring the Majorana entropy $S_M=k_B\log (2^{\frac{1}{2}})$ may uniquely reveal whether an initial equilibrium state of a nanoscale device is of Majorana nature and subsequent operations deal with an essentially nonlocal pair of non-Abelian Majorana bound states and not with trivial or other accidental non-Abelian states. However, in realistic setups both Majorana modes are inevitably involved in tunneling processes. We show that even when the tunneling amplitude of one Majorana mode is significantly suppressed, the Majorana entropy ruins and straightforward experiments will in general detect entropy $S\ll S_M$. To avoid this general problem we present a mechanism of the Majorana entropy revival via the tunneling phases of the Majorana modes and demonstrate that to successfully observe the universal Majorana plateau $S=S_M$ one should intelligently tune the tunneling phases instead of leaving them uncontrolled. Practical feasibility of appropriate Majorana entropy measurements is supported by an example with parameters well achievable in modern labs.

8 pages, 6 figures

References in corpus (8)

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• Introduction to topological superconductivity and Majorana fermions
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Cited by in corpus (10)

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• Majorana differential shot noise and its universal thermoelectric crossover
• Entanglement measures of Majorana bound states
• Can non-local conductance spectra conclusively signal Majorana zero modes? -- Insights from von Neumann entropy
• Thermoelectric processes of quantum normal-superconductor interfaces
• Nonequilibrium finite frequency resonances in differential quantum noise driven by Majorana interference
• Thermoelectric fluctuations of interfering Majorana bound states
• Fluctuation response of a minimal Kitaev chain in nonequilibrium states
• Creating and detecting poor man's Majorana bound states in interacting quantum dots
• Revealing universal Majorana fractionalization using differential shot noise and conductance in nonequilibrium states controlled by tunneling phases