Experimental protection of quantum coherence by using a phase-tunable image drive

Abstract

The protection of quantum coherence is essential for building a practical quantum computer able to manipulate, store and read quantum information with a high degree of fidelity. Recently, it has been proposed to increase the operation time of a qubit by means of strong pulses to achieve a dynamical decoupling of the qubit from its environment. We propose and demonstrate a simple and highly efficient alternative route based on Floquet modes, which increases the Rabi decay time ($$T_R$$ T R ) in a number of materials with different spin Hamiltonians and environments. We demonstrate the regime $$T_R \approx T_1$$ T R ≈ T 1 with $$T_1$$ T 1 the relaxation time, thus providing a route for spin qubits and spin ensembles to be used in quantum information processing and storage.

Sustaining Rabi oscillations by using a phase-tunable image drive

“…[24] we demonstrate a protocol based on Floquet resonances [25] using two microwave drives acting in parallel on the quantum state of a qubit and able to increase the coherence time under drive up to the relaxation time within the experimental conditions of Ref. [24]. The main drive is induces imperfect Rabi oscillations while a circularly polarized second drive, of about two orders of magnitude smaller in amplitude, has the role of sustaining the oscillations.…”

“…In Ref. [24] we demonstrate a protocol based on Floquet resonances [25] using two microwave drives acting in parallel on the quantum state of a qubit and able to increase the coherence time under drive up to the relaxation time within the experimental conditions of Ref. [24].…”

“…This method was demonstrated in Ref. [24] on any initial state of spin systems with different anisotropies, spin sizes and spinorbit couplings. The protocol is universal and it should be applicable to other qubit implementations such as nuclear spins or superconducting qubits.…”

Observation of the high-order Mollow triplet by quantum mode control with concatenated continuous driving

“…Concatenated continuous driving has been explored in several works [17,18,[23][24][25][26][27][28][29][30][31][32], typically in the context of protecting a qubit against decoherence. Here we focus on the simplest scheme, where only a second modulation is applied to the first driving field.…”

“…To overcome the challenges associated with the driving power needed to reach the regime beyond the RWA, we use concatenated continuous driving (CCD). CCD is a continuous dynamical decoupling technique with multiple resonant modulated fields and has been studied before in the context of qubit coherence protection [17,18,[23][24][25][26][27][28][29][30][31][32]. Here we use the CCD technique to engineer an effective static field along the x direction and a single-tone AC field in the rotating frame (interaction picture) [24], as we show in Sec.…”