Demonstration of long-range correlations via susceptibility measurements in a one-dimensional superconducting Josephson spin chain

  1. Daniel M. Tennant,
  2. Xi Dai,
  3. Antonio J. Martinez,
  4. Robbyn Trappen,
  5. Denis Melanson,
  6. M. A. Yurtalan,
  7. Yongchao Tang,
  8. Salil Bedkihal,
  9. Rui Yang,
  10. Sergei Novikov,
  11. Jeffery A. Grover,
  12. Steven M. Disseler,
  13. James I. Basham,
  14. Rabindra Das,
  15. David K. Kim,
  16. Alexander J. Melville,
  17. Bethany M. Niedzielski,
  18. Steven J. Weber,
  19. Jonilyn L. Yoder,
  20. Andrew J. Kerman,
  21. Evgeny Mozgunov,
  22. Daniel A. Lidar,
  23. and Adrian Lupascu
Spin chains have long been considered an effective medium for long-range interactions, entanglement generation, and quantum state transfer. In this work, we explore the properties of
a spin chain implemented with superconducting flux circuits, designed to act as a connectivity medium between two superconducting qubits. The susceptibility of the chain is probed and shown to support long-range, cross chain correlations. In addition, interactions between the two end qubits, mediated by the coupler chain, are demonstrated. This work has direct applicability in near term quantum annealing processors as a means of generating long-range, coherent coupling between qubits.