Single-hole tunneling into a strain-induced SiGe quantum ring - art. no. 161304

摘要

We have observed single-hole tunneling and Coulomb blockade in the resonant tunneling characteristics of an ultrasmall Si/SiGe strained vertical quantum dot. The current steps near the tunneling threshold are due to tunneling of the holes from the emitter to the doubly degenerate ground state of the strain-induced quantum ring in the vertical quantum dot, and the spacing of the steps gives the charging energy of the quantum ring. When a magnetic field is applied parallel to the tunneling direction, the evolution of the single-hole tunneling features reveals a cusp arising from the angular-momentum transition of the single-particle ground state of the quantum ring in the magnetic field. [References: 27]