Detuning dependence of capacitive coupling for quantum dot hybrid qubits*

Implementation of robust two-qubit entangling gates is necessary in order to form a universal set of multi-qubit operations. We derive the coupling form between two capacitively coupled qubits, each consisting of three electrons in a double quantum dot (i.e., two hybrid qubits), and show how the effective coupling behaves as a function of detuning. By pulsing the detuning adiabatically, we show how two-qubit entangling operations can be performed on relatively fast 100ns timescales. The entangling operations are then simulated in the presence of experimentally measured quasistatic noise. The fidelities are typically only around 90%, pointing to the need for further improvement via shaped-pulse optimization.