Spin Signature of Polarized Majorana Zero Modes
ORAL
Abstract
The motivation of this work is to understand the behavior of Majorana zero modes (MZMs) while also considering the spin degree of freedom of non-local fermionic modes to identify specific signatures of MZMs [1,2]. To achieve individual control over each spin channel, we propose a model for a hybrid qubit that consists of two U-shaped Kitaev wires with antiparallel polarizations. These wires are placed in contact with a quantum dot (QD) on both the left and right sides. This setup creates two antiparallel spin interferometers that host four MZMs at their edges. Based on this model, we suggest a measurement device similar to the one proposed by the Microsoft Azure Quantum group [3].
By analyzing the system's transitions, we can identify the key factors contributing to the formation of the characteristic zero-bias peak (ZBP). Our focus is on filtering the zero-energy transitions that arise from Majorana excitations and local Andreev reflections (LAR). Our results indicate that Majorana zero modes (MZMs) and LAR zero-energy transitions are essential for the formation of the Majorana peak. However, we also demonstrate that non-zero-energy transitions from LAR can impact the Majorana peak, potentially leading to "false positive" ZBPs in the system's conductance.
[1] Ribeiro RCB et al. Phys. Rev. B 105 205115, (2022).
[2] Bento Ribeiro R C, et al, Sci. Rep. 13 17965, (2023).
[3] M. Alcaraz Ramírez A. et al. Nature, 638:651–655, (2025).
By analyzing the system's transitions, we can identify the key factors contributing to the formation of the characteristic zero-bias peak (ZBP). Our focus is on filtering the zero-energy transitions that arise from Majorana excitations and local Andreev reflections (LAR). Our results indicate that Majorana zero modes (MZMs) and LAR zero-energy transitions are essential for the formation of the Majorana peak. However, we also demonstrate that non-zero-energy transitions from LAR can impact the Majorana peak, potentially leading to "false positive" ZBPs in the system's conductance.
[1] Ribeiro RCB et al. Phys. Rev. B 105 205115, (2022).
[2] Bento Ribeiro R C, et al, Sci. Rep. 13 17965, (2023).
[3] M. Alcaraz Ramírez A. et al. Nature, 638:651–655, (2025).
*The authors acknowledge financial support from CNPq, FAPESP, and FAPERJ.
–
Publication: Planned paper: Spin Signature of Polarized Majorana Zero Modes
This work constitutes part of the PHD Thesis of the first author: Tomas Sobreira.
Presenters
-
Marcos S. Figueira
- Federal Fluminense University