Proposal of a quantum phase transition in 3D Dirac-Weyl topological semimetals: qu...
| Grant number: | 15/23539-8 |
| Support type: | Scholarships in Brazil - Doctorate |
| Effective date (Start): | March 01, 2016 |
| Effective date (End): | February 29, 2020 |
| Field of knowledge: | Physical Sciences and Mathematics - Physics - Condensed Matter Physics |
| Principal Investigator: | Antonio Carlos Ferreira Seridonio |
| Grantee: | Luciano Henrique Siliano Ricco |
| Home Institution: | Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil |
Abstract In this project, we will explore theoretically the interplay between vacuum fluctuations, Majorana quasiparticles (MQPs) and bound states in the continuum (BICs) based on a non-trivial Kondo effect, in a system composed by two Kitaev chains within the topological phase, coupled to a QD hybridized with leads. It is well known that BICs emerge due to quantum interference processes, as for instance, the Fano effect. However, our preliminary results for the non-interacting case reveal a novel type of BICs, in which MQPs are trapped. As the MQPs of these Kitaev chains far apart build a delocalized fermion and consequently a qubit, we identify that the decay of these BICs is not connected to Fano and it occurs when finite fluctuations are observed in the vacuum composed by electron pairs for this qubit. This feature requires temporary broken of Pauli exclusion, which consists the novel manner of detecting the proposed BICs. From the experimental point of view, we also show that vacuum fluctuations can be induced just by changing the chain-dot couplings from symmetric to asymmetric. Hence, our current analysis shows how to perform the qubit storage within two delocalized BICs of MQPs and to access it when the vacuum fluctuates by means of a complete controllable way in quantum transport experiments. For the near feature, we want to answer if the current scenario remains by turning-on the Coulomb repulsion between the delocalized qubit and the QD. In such a case, a non-trivial Kondo effect is expected to rise, wherein the spin degree of freedom is not responsible, since the entire system is placed within a spinless regime for the existence of topological superconductivity. This phenomenon will be addressed by employing the following two methods: (i) the equation-of-motion (EOM) approach supported by a decoupling scheme on Green's functions of the system Hamiltonian, which will provide some analytical insights on the setup considered; and (ii) the numerical renormalization group (NRG) method, a powerful computational technique for impurity problems. (AU) | |