Talk with Lisa Sommer: Energy spectrum of holes in Ge/SiGe quantum dots

Title:

Energy spectrum of holes in Ge/SiGe quantum dots

Abstract:

Hole quantum dots in strained Ge/SiGe quantum wells are known for their anisotropic g-factor, which varies with the orbitals. Here we investigate the low-energy states of the first few holes confined in a quantum dot using Coulomb blockade addition spectroscopy and pulsed excited state spectroscopy as a function of the out-of-plane magnetic field. By comparing the addition spectrum with the excitation spectrum, we can extract orbital effects and hole interactions. Using gate electrodes, we reshape the quantum dot’s confinement potential, observing the voltage-controlled tunability of the out-of-plane gyromagnetic ratio. This talk will discuss the experimental methods, contrasts many-body and single-particle effects and explores the implications for spin qubit control.

Speaker:

Lisa Sommer from IBM Zurich