Integration of selectively grown topological insulator nanoribbons in superconducting quantum circuits

  1. Tobias W. Schmitt,
  2. Malcolm R. Connolly,
  3. Michael Schleenvoigt,
  4. Chenlu Liu,
  5. Oscar Kennedy,
  6. Abdur R. Jalil,
  7. Benjamin Bennemann,
  8. Stefan Trellenkamp,
  9. Florian Lentz,
  10. Elmar Neumann,
  11. Tobias Lindström,
  12. Sebastian E. de Graaf,
  13. Erwin Berenschot,
  14. Niels Tas,
  15. Gregor Mussler,
  16. Karl D. Petersson,
  17. Detlev Grützmacher,
  18. and Peter Schüffelgen
We report on the precise integration of nm-scale topological insulator Josephson junctions into mm-scale superconducting quantum circuits via selective area epitaxy and local stencil
lithography. By studying dielectric losses of superconducting microwave resonators fabricated on top of our selective area growth mask, we verify the compatibility of this in situ technique with microwave applications. We probe the microwave response of on-chip microwave cavities coupled to topological insulator-shunted superconducting qubit devices and observe a power dependence that indicates nonlinear qubit behaviour. Our method enables integration of complex networks of topological insulator nanostructures into superconducting circuits, paving the way for both novel voltage-controlled Josephson and topological qubits.