(Quantum Accelerator) Frequency Domain Quantum Communications using Electro-Optic Photonic Molecule
Abstract
We will perform a detailed study of frequency beam splitter (BS) concept at the quantum level. We will generate telecommunication- wavelength heralded single photons that are suitable for long-distance quantum communication using spontaneous parametric down-conversion (SPDC), and detect these using efficient superconducting nanowire single-photon detectors (SNSPDs). We will filter our heralded single photons to match the few-GHz acceptance bandwidth of one qubit mode of the photonic molecule, and then generate the BB84 states using appropriate amplitude and phase of microwave drive signals. Simply-speaking, these states correspond to frequency shifted and un-shifted beams as well as partially shifted beams with and without an added 180 deg. phase shift. The filtering step employs an integrated (tunable) single ring resonator. These states will then be measured using a photonic molecule by tailored microwave-driving, filtering, and photon detection. Notably, this work will allow us to benchmark our device for use in other quantum communication and computing protocols. We will assess key figures of merit of qubit measurement or process fidelity and on-chip loss, which, based on previous measurements, we expect to be >90% and ~1 dB, which is ideal for BB84 and more complex protocols. As a stretch goal, we will multiplex our BB84 setup and create a device array that allows simultaneous encoding and measurements of multiplexed states. This step will not only demonstrate the potential for high-rate quantum communications, but also allow a detailed study of cross-channel decoherence. This must be carefully scrutinized not only due to the potential of more errors, but also because it could open security loopholes in BB84 quantum communications that must be accounted for.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110056XX0
Entities
People
- Marko Loncar
Organizations
- Air Force Office of Scientific Research
- President and Fellows of Harvard College
- United States Air Force