The stimulated Raman adiabatic passage (STIRAP) allows selective, coherent population transfer in a three-level quantum system by the adiabatic control of two suitably chosen envelopes and delayed laser pulses. However, the long operation time involved with the adiabatic protocols makes them more susceptible to decay and decoherence. A shortcut-to-adiabaticity technique, namely, counterdiabatic driving (CD), suppresses the decoherence-induced loss by speeding up the STIRAP process, thereby enhancing the efficiency and fidelity of population transfer. The superadiabatic STIRAP (saSTIRAP) method requires the application of a shortcut drive or CD pulse, which couples the coherently trapped states in a three-level quantum system. Hence, the closed-loop $\mathrm{\ensuremath{\Lambda}}$ system consisting of all electric dipole-allowed transitions is an essential requirement for saSTIRAP, which is rarely admissible in a natural atom. This paper theoretically investigates an experimentally feasible model for implementing saSTIRAP using a closed-loop $\mathrm{\ensuremath{\Lambda}}$ system with doubly dressed polariton states in a driven circuit QED system. We show a population transfer with efficiencies close to
80.75 and
98.10 with fidelities of
89.86 and
99.04 for the resonant STIRAP and saSTIRAP protocols, respectively, with experimentally feasible parameters. The efficiency of the population transfer can be further increased by improving the coherence times of the cavity and the transmon qubit. This work may be useful in designing fast, efficient quantum gates for applications in quantum technologies.
The superadiabatic basis scheme developed by Berry [Proc. R. Soc. London 429, 61 (1990)] is used to analyze adiabatic population transfer in the \ensuremath{\Lambda} system in what is known as the counterintuitive pulse scheme. For a specific choice of pulses, we find that the diabatic loss is given by the exponentially small (8-4\ensuremath{\surd}2)exp(-2/\ensuremath{\epsilon}), where \ensuremath{\epsilon} is a small parameter describing the adiabaticity of the process. We thus establish the connection between population transfer in the \ensuremath{\Lambda} system and general adiabatic transition theory. We project numerical solutions onto superadiabatic basis states for the real three-level system and show how the history of population transfer has a very compact and universal history in one particular superadiabatic basis.
We implemented the superadiabatic population transfer within the nonadiabatic regime in a two-level superconducting qubit system. To realize the superadiabatic procedure, we added an additional term in the Hamiltonian, introducing an auxiliary counter-diabatic field to cancel the nonadiabatic contribution in the evolution. Based on the superadiabatic procedure, we further demonstrated quantum Phase and NOT gates. These operations, which possess both of the fast and robust features, are promising for quantum information processing.