Topology, cosmic strings and quantum dynamics _ a case study with graphene

6th International Workshop DICE2012 Spacetime – Matter – Quantum Mechanics: From the Planck Scale to Emergent Phenomena

物理学;力学

Chakraborty, Baishali^1 ; Gupta, Kumar S.^1 ; Sen, Siddhartha^2

Theory Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700064, India^1

CRANN, Trinity College Dublin, Dublin 2, Ireland^2

关键词: Coulomb charges;    Critical regimes;    Critical strength;    Graphene cones;    Local density of state;    Quantum dynamics;    Sample topology;    Topological defect;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/442/1/012017/pdf
DOI  :  10.1088/1742-6596/442/1/012017

学科分类：力学，机械学

来源: IOP

【 摘 要 】

We explore the possibility to study the quantum dynamics of Dirac fermions in presence of a cosmic string by introducing a conical topological defect in gapped graphene in the presence of a Coulomb charge. When the Coulomb charge exceeds a certain critical strength, quantum instability sets in. Below the critical regime and for certain values of the system parameters, the allowed boundary conditions in gapped graphene cone can be classified in terms of a single real quantity. Observables such as local density of states, scattering phase shifts and the bound state spectra are dependent on the value of this real parameter, which has to be determined empirically. For a supercritical Coulomb charge, we analyze the system with a regularized potential as well as with a zigzag boundary condition and find the effect of the sample topology on the observable features of the system.