Session A69: Hybrid Quantum Light-Matter Systems

Superconducting-qubit readout via low-backaction electro-optic transduction

Entangling superconducting qubits though optical interconnects will be critical for distributing quantum information from superconducting quantum processors through a future quantum internet.  However, transducing quantum signals between the microwave and optical domain remains an outstanding goal and interfacing superconducting qubits with electro-optic elements presents significant challenges due to the deleterious effects of optical photons on superconductors.  Here I will discuss results where we demonstrate readout of a superconducting transmon qubit via a continuously operated electro-optic transducer.  The modularity of the transducer and circuit QED system used in this work enable complete isolation of the qubit from optical photons, and backaction on the qubit from the transducer is smaller than that imparted by thermal radiation from the local environment.  Progress towards the transduction of quantum signals from a superconducting qubit through an electro-optomechanical transducer will be discussed.  

    

An integrated photonic engine for programmable atomic control

Scaled atomic qubit technologies require solutions for scalable optical control. We propose and demonstrate a reconfigurable architecture for multi-site control based on holography and integrated photonic circuitry. This integrated circuitry consists of arrays of fast thin-film-lithium-niobate modulators, with visible-spectrum transparency to enable the interrogation of important visible-wavelength transitions in leading atomic systems. Using a prototype sixteen-channel array, we demonstrate techniques for stabilizing temporal and cross-channel noise, for spectral modulation, and for spatially steering the power in each channel toward target atomic sites. We discuss the application of this platform to a homogeneous set of silicon-vacancy artificial atoms in diamond, along with extensions of this prototype system towards implementing a fast coherent display for projecting individual control beams onto thousands of atoms.   

Author not Attending

The hybrid approach of combining superconducting and photonic quantum technologies promises to realize large-scale quantum networks, where quantum information is processed by superconducting circuits and transmitted with optical photons. Quantum transducers, which coherently interface superconducting and photonic circuits, is indispensable for this approach. To reach the ideal performance with high quantum capacity, low added noise, and large conversion bandwidth, innovations in both the transduction hardware and protocols are required. In this talk, I will present our recent advances in exploring new transduction hardware platforms based on cavity electro-optical and cavity piezo-optomechanical systems. Moreover, I will introduce novel transduction protocols beyond the simple direct conversion scheme. By leveraging advanced methods such as continuous-variable teleportation, parametric amplification, and quantum information pre/post-processing, the transduction capacity can be increased with the same hardware performance.   

Non-reciprocal interactions and entanglement between optically levitated nanoparticles

Optically levitating dielectric nanoparticles in ultra-high vacuum, where their motion can be cooled into the deep quantum regime, provides a promising platform for force and torque sensing and for high-mass tests of quantum physics. In this talk I will review recent results on the coupled dynamics of co-levitated nanoparticles interacting via optical binding and via electrostatic forces. Further, I will dicsuss how these experiments open the door for probing non-reciprocal interactions [1] and entanglement [2,3] in nanoparticle arrays.

[1] Rieser, Ciampini, Rudolph, Kiesel, Hornberger, Stickler, Aspelmeyer, and Delic, Science 377, 987 (2022)

[2] Rudolph, Hornberger, and Stickler, Phys. Rev. A 101, 011804 (2020).

[3] Rudolph, Delic, Aspelmeyer, Hornberger, and Stickler, Phys. Rev. Lett. (in press)   

Microwave-to-optics conversion in the quantum ground state

Microwave-to-optical quantum converters represent an indispensable component for quantum communication in future quantum networks. To maintain quantum coherence, it is critical for such devices to operate at milli-Kelvin temperatures in the quantum ground state. Integrating photonics with superconductors at milli-Kelvin temperatures is particularly challenging since the optical excitation leads to excess microwave noise, thus placing the device systems in a thermal state as opposed to the desired ground state. In this work, I will present our experimental progress in demonstrating efficient bidirectional microwave-to-optical conversion with an electro-optic device fabricated on an integrated photonic platform in a milli-Kelvin environment. Our device operates near its quantum ground state and meanwhile offers high conversion efficiency that is suitable for building a two-node quantum network through heralding protocols.