Lightly strained germanium quantum wells with hole mobility exceeding one million
Mario Lodari, O. Kong, M. J. Rendell, Alberto Tosato, Amir Sammak, Menno Veldhorst, A. R. Hamilton, Giordano Scappucci
Abstract
We demonstrate that a lightly strained germanium channel (ε//=−0.41%) in an undoped Ge/Si0.1Ge0.9 heterostructure field effect transistor supports a two-dimensional (2D) hole gas with mobility in excess of 1×106 cm2/Vs and percolation density less than 5×1010 cm−2. This low disorder 2D hole system shows tunable fractional quantum Hall effects at low densities and low magnetic fields. The low-disorder and small effective mass (0.068me) defines lightly strained germanium as a basis to tune the strength of the spin–orbit coupling for fast and coherent quantum hardware.
Topics & Concepts
GermaniumCondensed matter physicsElectron mobilityHeterojunctionEffective mass (spring–mass system)Materials scienceQuantum wellField-effect transistorMagnetic fieldCoupling (piping)Field (mathematics)OptoelectronicsTransistorPhysicsSiliconOpticsQuantum mechanicsMetallurgyMathematicsLaserPure mathematicsVoltageQuantum and electron transport phenomenaAdvancements in Semiconductor Devices and Circuit DesignTopological Materials and Phenomena