Superconducting two-qubit gates using tunable couplers and accelerated adiabatic evolution

Adiabatic evolution can be harnessed to design quantum gates which are remarkably robust against a variety of imperfections and system uncertainties; they unfortunately require extremely long gate times. Recent works [1,2] show how to mitigate this shortcoming using a shortcuts-to-adiabaticity (STA) approach, which through appropriate pulse modification can substantially accelerate adiabatic single-qubit gates. The accelerated gates are not only fast but still inherit the resilience to control-pulse imperfections. In this talk, I will extend STA quantum gate ideas to design a robust geometric two-qubit gate which can be readily applied to a variety of superconducting qubits such as fluxonia or transmons.  Our approach represents a new method for realizing gates in qubit systems where coupling is mediated by an auxiliary coupler qubit or bus mode, and provides unique advantages.  Further, while our approach is connected to Stimulated Raman Adiabatic Passage (STIRAP) protocol, it is considerably simpler (and less experimentally demanding) than the standard STIRAP-based geometric gate of Ref. [3]. I will give a detailed theoretical study of the performance of our two-qubit gate in a superconducting circuit consisting of two fluxonium qubits that interact via a coupling bus circuit.

[1] H. Ribeiro and A. A. Clerk, Phys. Rev. A 100, 032323 (2019).

[2] F Setiawan, P Groszkowski, H Ribeiro, AA Clerk, PRX Quantum 2 (3), 030306 (2021).

[3] L. M. Duan, J. I. Cirac and P. Zoller, Science 292, 1695 (2001).