The demonstration of a quantum link between microwave and optical frequencies would be an important step toward the realization of a quantum network of superconducting processors. A major impediment ...to quantum electro-optic transduction in all platforms explored to date is noise added by thermal occupation of modes involved in the transduction process, and it has proved difficult to realize low thermal occupancy concurrently with other desirable features like high duty cycle and high efficiency. In this work, we present an efficient and continuously operating electro-optomechanical transducer whose mechanical mode has been optically sideband cooled to its quantum ground state. The transducer achieves a maximum efficiency of 47% and minimum input-referred added noise of 3.2 photons in upconversion. Moreover, the thermal occupancy of the transducer’s microwave mode is minimally affected by continuous laser illumination with power more than 2 orders of magnitude greater than that required for optomechanical ground-state cooling.
Entangling microwave-frequency superconducting quantum processors through optical light at ambient temperature would enable means of secure communication and distributed quantum information ...processing
. However, transducing quantum signals between these disparate regimes of the electro-magnetic spectrum remains an outstanding goal
, and interfacing superconducting qubits, which are constrained to operate at millikelvin temperatures, with electro-optic transducers presents considerable challenges owing to the deleterious effects of optical photons on superconductors
. Moreover, many remote entanglement protocols
require multiple qubit gates both preceding and following the upconversion of the quantum state, and thus an ideal transducer should impart minimal backaction
on the qubit. Here we demonstrate readout of a superconducting transmon qubit through a low-backaction electro-optomechanical transducer. The modular nature of the transducer and circuit quantum electrodynamics system used in this work enable complete isolation of the qubit from optical photons, and the backaction on the qubit from the transducer is less than that imparted by thermal radiation from the environment. Moderate improvements in the transducer bandwidth and the added noise will enable us to leverage the full suite of tools available in circuit quantum electrodynamics to demonstrate transduction of non-classical signals from a superconducting qubit to the optical domain.
Transparent polycrystalline ceramic scintillators based on the garnet structure and incorporating gadolinium for high stopping power are being developed for use in gamma spectrometers. Optimization ...of energy resolution for gamma spectroscopy involves refining the material composition for high stopping and high light yield, developing ceramics fabrication methodology for material homogeneity, as well as selecting the size and geometry of the scintillator to match the photodetector characteristics and readout electronics. We have demonstrated energy resolution of 4% at 662 keV for 0.05 cm 3 GYGAG(Ce) ceramics with photodiode readout, and 4.9% resolution at 662 keV for 18 cm 3 GYGAG(Ce) ceramics and PMT readout. Comparative gamma spectra acquired with GYGAG(Ce) and NaI(Tl) depict the higher resolution of GYGAG(Ce) for radioisotope identification applications. Light yield non-proportionality of garnets fabricated following different methods reveal that the fundamental shapes of the light yield dependence on energy are not intrinsic to the crystal structure, but may instead depend on trap state distributions. With exposure to 9 MeV Brehmsstrahlung radiation, we also find that GYGAG(Ce) ceramics exhibit excellent radiation hardness.
Assembling and maintaining large arrays of individually addressable atoms is a key requirement for continued scaling of neutral-atom-based quantum computers and simulators. In this work, we ...demonstrate a new paradigm for assembly of atomic arrays, based on a synergistic combination of optical tweezers and cavity-enhanced optical lattices, and the incremental filling of a target array from a repetitively filled reservoir. In this protocol, the tweezers provide microscopic rearrangement of atoms, while the cavity-enhanced lattices enable the creation of large numbers of optical traps with sufficient depth for rapid low-loss imaging of atoms. We apply this protocol to demonstrate near-deterministic filling (99% per-site occupancy) of 1225-site arrays of optical traps. Because the reservoir is repeatedly filled with fresh atoms, the array can be maintained in a filled state indefinitely. We anticipate that this protocol will be compatible with mid-circuit reloading of atoms into a quantum processor, which will be a key capability for running large-scale error-corrected quantum computations whose durations exceed the lifetime of a single atom in the system.
A fast digitization system for a high-efficiency scintillating tile hodoscope has been developed for the muon g-2 experiment. Light pulses from the tiles are amplified by a Philips 64-channel ...photomultiplier tube. Electrical signals are both discriminated and stored locally in custom NIM modules as four 16-bit words. Digital information is then pumped via shielded 'phone' cables to a remote custom VME module which serves as a data buffer and computer interface. Testbeam performance of PSD and digitization system is discussed.
Measurement-based quantum error correction relies on the ability to determine the state of a subset of qubits (ancillae) within a processor without revealing or disturbing the state of the remaining ...qubits. Among neutral-atom based platforms, a scalable, high-fidelity approach to mid-circuit measurement that retains the ancilla qubits in a state suitable for future operations has not yet been demonstrated. In this work, we perform imaging using a narrow-linewidth transition in an array of tweezer-confined \(^{171}\)Yb atoms to demonstrate nondestructive state-selective and site-selective detection. By applying site-specific light shifts, selected atoms within the array can be hidden from imaging light, which allows a subset of qubits to be measured while causing only percent-level errors on the remaining qubits. As a proof-of-principle demonstration of conditional operations based on the results of the mid-circuit measurements, and of our ability to reuse ancilla qubits, we perform conditional refilling of ancilla sites to correct for occasional atom loss, while maintaining the coherence of data qubits. Looking towards true continuous operation, we demonstrate loading of a magneto-optical trap with a minimal degree of qubit decoherence.
Electromagnetic calorimeters for the BNL muon ( g−2) experiment Sedykh, S.A; Blackburn, J.R; Bunker, B.D ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2000, Letnik:
455, Številka:
2
Journal Article
Recenzirano
A set of 24 lead/scintillating fiber electromagnetic calorimeters has been constructed for the new muon (
g−2) experiment at the Brookhaven AGS. These calorimeters were designed to provide very good ...energy resolution for electrons up to 3 GeV while also yielding excellent timing information. Special requirements in the experiment related to the uniformity of response, the short-term gain and timing stability, and the neutron background led to several unusual design features. The calorimeters were tested and calibrated with electrons in the energy range 0.5–4.0 GeV and have been installed and used in the muon storage ring. The design criteria, construction, and performance of the system are described.
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