Towards a Rydberg Quantum Processor with Fast Mid-circuit Readout

Two prerequisites for a scaleable, error-corrected neutral atom quantum computer are mid-circuit readout and two-qubit entangling gates. Mid-circuit readout must be high fidelity and faster than system decoherence times without disturbing qubits not under measurement. These requirements can be achieved via atomic fluorescence measurements with an optical cavity in the strong coupling regime. Two-qubit entangling gates can be achieved via site-selective Rydberg excitations. It is thus compelling to combine the two components in a single experimental apparatus.

I will discuss our efforts towards realizing a tweezed neutral atom array with Rydberg excitations and fast cavity-based readout, with particular focus on the control of stray electric fields emitted by cavity piezoelectric actuators that can induce large DC Stark shifts on highly polarizable Rydberg atoms. I will also discuss our findings on two-photon absorption spectroscopy for the identification of high-lying Rydberg resonances, which yields an enhanced spectroscopic signal over conventional electromagnetic-induced transparency techniques in an inverted wavelength configuration. Such a technique can be useful for mapping out the spectrum of Rydberg states for a new atomic species that requires an inverted wavelength two-photon excitation or for frequency locking of the coupling laser.