  Hole spin qubits in planar Ge heterostructures are one of the frontrunner
platforms for scalable quantum computers. In these systems, the spin-orbit
interactions permit efficient all-electric qubit control. We propose a minimal
design modification of planar devices that enhances these interactions by
orders of magnitude and enables low power ultrafast qubit operations in the GHz
range. Our approach is based on an asymmetric potential that strongly squeezes
the quantum dot in one direction. This confinement-induced spin-orbit
interaction does not rely on microscopic details of the device such as growth
direction or strain, and could be turned on and off on demand in
state-of-the-art qubits.
