Impact of Majorana fermions on the Kondo state in the carbon nanotube quantum dot
Year: 2025
Type: article
Abstract: We have studied the quantum conductance of the Kondo state in the carbon nanotube quantum dot (CNTQD) with side-attached multi-Majorana fermion states in topological superconductors (TSCs). The zero-energy Majorana fermions interfere with the fourfold degenerate states of the CNTQD in the spin-orbital Kondo regime. Using the extended Kotliar-Ruckenstein slave-boson mean-field approach, we have analyzed the symmetry reduction of the SU(4) Kondo effect to the SU⋆(3) Kondo state with a fractional charge in the system by increasing the tunneling strength to a single Majorana fermion (TSC). We observed the fractional quantum conductance, the enhancement of the thermoelectric power with two compensation points, the fractional linear and nonlinear Fano factor (F K ), and the spin polarization of the conductance. Two Majoranas (2TSC) in conjunction with the CNTQD have reduced the spin-orbital Kondo effect to the SU⋆(2) Kondo state with 2e in the system. The F K contains information about the effective charge and the interaction between the quasiparticles, two- and three-body correlators and identifies the broken symmetry of the Kondo state. Furthermore, we have shown that the device coupled with three Majorana fermions (3TSC) achieves a quantized conductance 5/2(e 2/h), preserves the U⋆(1) charge symmetry at the electron-hole symmetry point and manifests the increase in nonlinear current and shot noise due to the entanglement in octuplets with opposite charge-leaking states.
Author: D Krychowski
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,880
OpenAlex ID: W4407399976