Implementing universal control in encoded exchange-only Si/SiGe spin qubits

Exchange-only silicon spin qubits are an encouraging platform for quantum computing mainly due to the existing strengths of silicon-based material development and CMOS fabrication techniques. However, this encoding scheme comes at the cost of increased number of spins-per-qubit and increased number of pulses-per-quantum gate in the encoded computational space. Recently, HRL has implemented encoded logic on arrays of six quantum dots in Si/SiGe [1]. This challenging experiment required key advances in fabrication, automation, calibration, software and analysis. In this talk, I will elaborate on several of these advances that enabled exchange-only quantum computing in arrays of dots, including pathways to reduce error and to increase scale. The exchange-only encoding has built-in noise protection and utilizes a single physical control mechanism for all qubit initialization and control, which together form a promising pathway towards fault tolerance.



[1] A. Weinstein et al., arXiv:2202.03605 (2022)