Adiabatic two-qubit gates of capacitively coupled quantum dot hybrid qubits*

Semiconductor quantum dot qubits have progressed greatly over the past several years, with two-qubit gates realized by several groups. So far, the fidelities reported for these gates are still below the error correction threshold. Here, we model a system consisting of two capacitively-coupled quantum dot hybrid qubits, and optimize the adiabatic electrical pulses used to entangle these qubits. We find a simple pulse that yields a CZ gate with greater than 99% fidelity in the presence of a quasistatic charge noise distribution with standard deviation 1 µeV. Further, we introduce the concept of a “dynamical sweet spot” which can be used to develop pulses that decrease the infidelity by a factor of >5.