Holonomic quantum computing with single-electron spin qubits at zero magnetic field

Single-electron spin qubits in semiconductor quantum dots provide a promising platform for quantum computing. Traditionally, such qubits are operated at a finite magnetic field, using resonant control with microwave pulses. A twofold major technological simplification of the platform would be achieved by operating the qubits (1) without a magnet, and (2) with baseband voltage pulses only. In this work, we propose such an architecture, and provide a roadmap of intermediate experimental milestones toward scaling up. The roadmap is based on recent progress with hole spin qubits in planar Germanium quantum wells.