Scalable local addressing of atomic qubits using integrated photonics

Robert Niffenegger, Jules Stuart, David Reens +11 more

Julian Rasmus Bankwitz, Erik Jung, Philipp Schultzen +8 more

Integrated photonic arbitrary waveform generators allow significant advancements in scalability and performance of single qubit addressing in neutral atom quantum computers. In this work, we showcase a hybrid Si3N4/LiNbO3electro-optic circuit for single-atom controll, achieving switching speeds surpassing 15 GHz bandwidth and 50 dB extinction ratio.

Stefano Paesani

D. Andrew Golter, Genevieve Clark, Tareq El Dandachi +11 more

A central goal in many quantum information processing applications is a network of quantum memories that can be entangled with each other while being individually controlled and measured with high fidelity. This goal has motivated the development of programmable photonic integrated circuits (PICs) with integrated spin quantum memories using diamond color center spin-photon interfaces. However, this approach introduces a challenge into the microwave control of individual spins within closely packed registers. Here, we present a quantum memory-integrated photonics platform capable of (i) the integration of multiple diamond color center spins into a cryogenically compatible, high-speed programmable PIC platform, (ii) selective manipulation of individual spin qubits addressed via tunable magnetic field gradients, and (iii) simultaneous control of qubits using numerically optimized microwave pulse shaping. The combination of localized optical control, enabled by the PIC platform, together with selective spin manipulation opens the path to scalable quantum networks on intrachip and interchip platforms.

Stefano Paesani

Dylan A. Heberle, Christopher C. Tison, James Schneeloch +4 more

With the stability of integrated photonics at network nodes and the advantages of photons as flying qubits, photonic quantum information processing (PQIP) makes quantum networks increasingly scalable. However, scaling up PQIP requires the preparation of many identical single photons which is limited by the spectral distinguishability of integrated single-photon sources due to variations in fabrication or local environment. To address this, we introduce frequency auto-homogenization via group-velocity-matched downconversion to remove spectral distinguishability in varying quantum emitters. We present our theory using $χ^{(2)}$ quantum frequency conversion and show proof-of-principle data in a free-space optical setup.