HYBRID ATOM-SUPERCONDUCTOR QUANTUM INTERFACE
Abstract
The overall objective of the proposed research is to develop the foundation for a hybrid quantum interface between atomic and superconducting qubits. Developing a functional and scalable quantum computer utilizing only atomic or superconducting components presents significant challenges as each system has individual strengths and weaknesses. This proposal aims to leverage the benefits of the long coherence times of Rydberg atom systems amenable to quantum memories with the benefits of the fast gate times accessible in superconducting systems. The proposed three year effort seeks to take the first step toward a full hybrid interface system functioning in a dilution refrigerator by interfacing a trapped Rydberg atom qubit and a superconducting microwave cavity at 4K. Successful implementation of this scheme will allow the researchers to understand the physics and fabrication challenges associated with building a hybrid system functioning at millikelvin temperatures capable of entangling a single atom with a single microwave photon. This single atom-single microwave photon entanglement result would enhance the development of quantum computing and distributed quantum communication capabilities. Additionally, the functioning 4K system will provide a platform for fundamental studies of cavity quantum electrodynamics in the strong coupling regime and multiple experiments exploring this are planned. The overall technical approach is to incrementally move toward demonstrating coupling of the quantum state of a neutral Rydberg atom (cesium) to a microwave excitation of a superconducting thin-film resonator. The proposed scheme will first encode quantum information in the hyperfine clock states of laser cooled Cs atoms. The atoms will then be moved via optical or magnetic means to a position a few micrometers above the surface of a high-Q superconducting coplanar waveguide microwave resonator housed in a 4K helium cryostat. Entanglement between the Rydberg atom and microwave cavity will be achieved by coupling the microwave excitations of the resonator to transitions between the Rydberg states of the atom. Year one of the project will focus on characterizing coplanar waveguide resonators with 3D structures for enhanced field strength, proper transportation of atoms to the resonator area, and measurement of the atom-microwave photon coupling strength. Year two work will focus on characterizing the strong coupling regime of excited Rydberg atoms and the superconducting cavity, specifically cavity-induced Purcell enhancement of Rydberg atom lifetime. Year three work will be aimed at demonstrating entanglement between the Rydberg atom and coherent states of the cavity to realize high-contrast quantum nondemolition measurements of the atomic state. All of the work conducted to date will also be leveraged to commence designing the millikelvin experiment which will enable entanglement of a single atom with a single microwave photon.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1610133
Entities
People
- Mark Saffman
Organizations
- Army Contracting Command
- United States Army
- University of Wisconsin–Madison