公开(公告)号：US12175333B2

公开(公告)日：2024-12-24

申请号：US17496833

申请日：2021-10-08

Applicant: Massachusetts Institute of Technology

Inventor： Dirk Robert Englund ,  Stefan Ivanov Krastanov ,  Hamza Raniwala

IPC: G06N10/40

Abstract: The typical approach to transfer quantum information between two superconducting quantum computers is to transduce the quantum information into the optical regime at the first superconducting quantum computer, transmit the quantum information in the optical regime to the second superconducting quantum computer, and then transduce the quantum information back into the microwave regime at the second superconducting quantum computer. However, direct microwave-to-optical and optical-to-microwave transduction have low fidelity due to the low microwave-optical coupling rates and added noise. These problems compound in consecutive microwave-to-optical and optical-to-microwave transduction steps. We break this rate-fidelity trade-off by heralding end-to-end entanglement with one detected photon and teleportation. In contrast to cascaded direct transduction, our technology absorbs the low optical-microwave coupling efficiency into the entanglement heralding step. Our approach unifies and simplifies entanglement generation between superconducting devices and other physical modalities in quantum networks.

公开(公告)号：US20230208628A1

公开(公告)日：2023-06-29

申请号：US18146085

申请日：2022-12-23

Applicant: Massachusetts Institute of Technology

Inventor： Stefan Ivanov Krastanov ,  Hamza Raniwala ,  Hanfeng WANG ,  Matthew Edwin TRUSHEIM ,  Laura KIM ,  Dirk Robert ENGLUND

IPC: H04L9/08 ,  H04B10/70

CPC classification number: H04L9/0855 ,  H04B10/70

Abstract: A 1D diamond nanobeam can act as a coherent mechanical interface between spin defect centers in diamond and telecom optical modes. The nanobeam includes embedded mechanical and electric field concentrators with mechanical and optical mode volumes of Vmech/Λp3 ˜10−5 and Vopt/λ3 ˜10−3, respectively. With a Group IV vacancy in the concentrator, the nanobeam can operate at spin-mechanical coupling rates approaching 40 MHz with high acousto-optical couplings. This nanobeam, used in an entanglement heralding scheme, can provide high-fidelity Bell pairs between quantum repeaters. Using the mechanical interface as an intermediary between the optical and spin subsystems enables addressing the spin defect center with telecom optics, bypassing the native wavelength of the spin. As the spin is never optically excited or addressed, the device can operate at temperatures up to 40 K with no appreciable spectral diffusion, limited by thermal losses. Optomechanical devices with high spin-mechanical coupling can be useful for quantum repeaters.