Characterizing the Electromagnetic Field Distribution of High Frequency Electron Spin Resonance Lines

A scanning tunneling microscope (STM) can be used for atomically precise hydrogen-depassivation lithography which enables the creation of scalable donor-based solid-state quantum simulation and computing architectures in silicon. Donor dot devices in silicon have been fabricated, and in these systems, qubits are represented as either the spin of a single valence electron or the nuclear spin of a phosphorous donor atom. Coherent manipulation of semiconductor spin qubits requires an oscillating electromagnetic field, and the strength of this field is directly proportional to the Rabi oscillation frequency. High frequency (40 GHz regime) on-chip coplanar waveguides can be modified to fabricate Oersted, or electron spin resonance (ESR), lines using standard photolithography techniques. Coupling a symmetrical opposing Oersted line to the first results in an antenna that can be utilized to characterize the electromagnetic field strength surrounding the ESR line. Simulations of the novel on-chip Oersted-antenna device wire bonded to a custom printed circuit board (PCB) has shown to be consistent with measured S-parameters. The nanoscale receiver antenna has proven to be a useful tool in optimizing ESR geometry and design.