Fano interference and a slight fluctuation of the Majorana hallmark

Abstract

According to the Phys. Rev. B 84, 201308(R) (2011), an isolated Majorana state bound to one edge of a long enough Kitaev chain in the topological phase and connected to a quantum dot, results in a robust transmittance of $1/2$ at zero-bias. In this work, we show that the removal of such a hallmark can be achieved by using a metallic surface hosting two adatoms in a scenario where there is a lack of symmetry in the Fano effect, which is feasible by coupling the Kitaev chain to one of these adatoms. Thus in order to detect this feature experimentally, one should apply the following two-stage procedure: (i) first, attached to the adatoms, one has to lock AFM tips in opposite gate voltages (symmetric detuning of the levels) and measure by an STM tip, the zero-bias conductance; (ii) thereafter, the measurement of the conductance is repeated with the gates swapped. For the absolute value of the detuning away from the Fermi energy and in the case of strong coupling tip-host, this approach reveals in the transmittance, a persistent dip placed at zero-bias and immune to the aforementioned permutation, but characterized by an amplitude that fluctuates slightly around $1/2$. However, in the case of a tip acting as a probe, the adatom decoupled from the Kitaev chain becomes completely inert and no fluctuation is observed. Therefore, the STM tip must be considered in the same footing as the "host+adatoms" system. As a result, we have found that despite the small difference between these two Majorana dips, the zero-bias transmittance as a function of the symmetric detuning yields two distinct behaviors, in which one of them is unpredictable by the standard Fano's theory. Therefore, to access such a non trivial pattern of Fano interference, the hypothesis of the STM tip acting as a probe should be discarded.

References in corpus (30)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Unpaired Majorana fermions in quantum wires
• Topological Insulators in Three Dimensions
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Fano resonances in nanoscale structures
• New directions in the pursuit of Majorana fermions in solid state systems
• Kondo Physics in a Single Electron Transistor
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• A generic new platform for topological quantum computation using semiconductor heterostructures
• A Tunable Kondo Effect in Quantum Dots
• Zero-bias peaks in spin-orbit coupled superconducting wires with and without Majorana end-states
• The role of magnetic anisotropy in the Kondo effect
• Observing Majorana Bound States in p-wave Superconductors Using Noise Measurements in Tunneling Experiments
• Detecting a Majorana-Fermion Zero Mode Using a Quantum Dot
• Non-Abelian operations on Majorana fermions via single charge control
• Parity qubits and poor man's Majorana bound states in double quantum dots
• Scheme to measure Majorana fermion lifetimes using a quantum dot
• Quantum information transfer between topological and spin qubit systems
• Majorana bound states and non-local spin correlations in a quantum wire on an unconventional superconductor
• Zero bias conductance peak in Majorana wires made of semiconductor-superconductor hybrid structures
• Probing the existence and dynamics of Majorana fermion via transport through a quantum dot
• Majorana fermions in density modulated p-wave superconducting wires
• Nonlocal noise cross-correlation mediated by entangled Majorana fermions
• Local density of states in metal - topological superconductor hybrid systems
• First-principles Calculation of the Single Impurity Surface Kondo Resonance
• Manipulating Majorana Fermions in Quantum Nanowires with Broken Inversion Symmetry
• Majorana fermions in an out-of-equilibrium topological superconducting wire: an exact microscopic transport analysis of a p-wave open chain coupled to normal leads
• Josephson effect in superconducting wires supporting multiple Majorana edge states
• The graphene sheet versus the 2DEG: a relativistic Fano spin-filter via STM and AFM tips
• Non-Zeeman splitting for a spin-resolved STM with a Kondo adatom in a spin-polarized two-dimensional electron gas

Cited by in corpus (6)

• Majorana oscillations modulated by Fano interference and dregree of non-locality in a topological superconducting nanowire-quantum dot system
• Spin-resolved interference due to Majorana state on interface between normal and superconducting leads
• Probing the Antisymmetric Fano Interference Assisted by a Majorana Fermion
• Unveiling Majorana Quasiparticles by a Quantum Phase Transition: Proposal of a Current Switch
• Effect of Interdots Electronic Repulsion in the Majorana Signature for a Double Dot Interferometer
• Fano fingerprints of Majoranas in Kitaev dimers of superconducting adatoms