Entangled state preparation method and device based on superconducting quantum bits and Rydberg atoms

Abstract

The invention discloses an entangled state preparation method and device based on superconducting quantum bits and Rydberg atoms, and the method comprises the steps: enabling the superconducting quantum bits to be in resonant coupling with a selected mode of a superconducting transmission line cavity, and enabling two Rydberg states of the Rydberg atoms to be in resonant coupling with a superconducting planar waveguide cavity / superconducting planar LC resonant cavity; resonating and coupling the superconducting planar waveguide cavity / superconducting planar LC resonant cavity with the selectedmode of the superconducting transmission line cavity; adjusting the coupling strength g1 of the superconducting quantum bit and the superconducting transmission line cavity and the coupling strengthg2 of the Rydberg atom and the superconducting planar waveguide cavity / superconducting planar LC resonant cavity, so that the coupling strength J between the Rydberg atom and the superconducting transmission line cavity and the coupling strength J between the Rydberg atom and the superconducting planar waveguide cavity / superconducting planar LC resonant cavity meet the relationship; by means of two strong microwave driving fields, an unconventional geometric quantum gate is realized, and the preparation of the maximum entangled state is completed. The influence of a laser field and a magneticfield required by Rydberg atoms and a radiation cooling superconducting coaxial cable on the coherence of superconducting quantum bits can be reduced.

Description

technical field [0001] The invention relates to the field of quantum information technology, in particular to a method and device for preparing an entangled state of superconducting qubits and Rydberg atoms through a thermally coupled cavity, which can be applied to a wide range of quantum information fields (including quantum storage, quantum communication and Quantum computing and other technical directions). Background technique [0002] The quantum interface or entanglement between different quantum systems (superconducting qubits, trapped ions, quantum dots, diamond color centers, cold atoms, doped ion crystals, photons, phonons, etc.) is crucial to realize distributed quantum computing. Different experimental systems have their own advantages and disadvantages. For example, superconducting qubits have fast operation speed and strong scalability, but they work in the microwave band and lack optical band transitions. They need the assistance of other quantum systems to i...

AI Technical Summary

Problems solved by technology

Installing superconducting chips and imprisoning Rydberg atoms on the same refrigeration platform will reduce the coherence of superconducting qubits, which is not conducive to quantum state transmission or entanglement

Placing superconducting chips and Rydberg atoms on different refrigeration platforms is one of the ways to solve the problem that the coherence of superconducting qubits is affected by laser light, but there is a temporary lack of high-fidelity nonlocal superconducting qubits and Rydberg atoms. quantum interface or entanglement scheme

[0004] The nonlocal quantum interface or entanglement on different platforms has the disadvantages of low fidelity and slow speed compared to local quantum state transmission. Therefore, it is necessary to propose a technical means that can realize superconducting qubits and Non-local quantum interface or entanglement between cold atoms, so as not to affect the coherence of superconducting qubits; on the other hand, the fidelity and speed must reach the performance of local systems, that is, higher than the realization of quantum networks or distributed quantum Calculated Threshold

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