Initialization of Single Spin Dressed States using Shortcuts to Adiabaticity

Abstract

We demonstrate the use of shortcuts to adiabaticity protocols for initialisation, readout, and coherent control of dressed states generated by closed-contour, coherent driving of a single spin. Such dressed states have recently been shown to exhibit efficient coherence protection, beyond what their two-level counterparts can offer. Our state transfer protocols yield a transfer fidelity of ∼ 99.4(2) % while accelerating the transfer speed by a factor of 2.6 compared to the adiabatic approach. We show bi-directionality of the accelerated state transfer, which we employ for direct dressed state population readout after coherent manipulation in the dressed state manifold. Our results enable direct and efficient access to coherence-protected dressed states of individual spins and thereby offer attractive avenues for applications in quantum information processing or quantum sensing.

Shortcuts to adiabaticity: Concepts, methods, and applications

“…The challenges and prospects of Optimal Control Theory for quantum systems which overlap with those of shortcuts to adiabaticity are discussed in the review articles Glaser et al (2015) and Koch (2016).…”

“…to which extent the target state is reachable; and control design, possibly including reservoir engineering. A framework to draw the frontiers of controllability is highly desirable for quantum control in open systems (Glaser et al, 2015;Koch, 2016), but note that shortcuts may be applied even if the system is not fully controllable (Petiziol et al, 2018).…”

Accelerated adiabatic quantum gates: Optimizing speed versus robustness

“…(21) Comparing against Eqs. (17) and (20), we see that to leading order, non-adiabatic errors do not change the nature of the gate: we still have a pure geometric operation on the qubit subspace and the latter is still decoupled from the auxiliary subspace. Non-adiabatic errors only change the rotation performed on the auxiliary levels.…”

Quantum control via enhanced shortcuts to adiabaticity

“…STA methods have been used to control a variety of Hamiltonians, such as harmonic-oscillator potentials [23][24][25] and two-level [12,14], three-level [26,27], and four-level [28] systems. They have been utilized experimentally for trapped ions [29], superconducting qubits [30,31], nitrogen-vacancy centers [32,33], ultracold atoms [34], and Bose-Einstein condensates [35]. However there are still many Hamiltonians that are not tractable with standard STA techniques.…”