Robust entanglement by continuous dynamical decoupling of the J-coupling interaction. (5th November 2021)

• Record Type: Journal Article
• Authors: Valahu, C H; Lawrence, A M; Weidt, S; Hensinger, W K
• Is Part Of: New journal of physics. Volume 23:Number 11(2021)
• Publication Date: 2021-11-05
• Subjects: trapped ions -- dressed states -- continuous dynamical decoupling -- microwave QIP -- robust entangling gates -- quantum computing; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ac320e
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We propose a σ z ⊗ σ z laser-free entangling gate which uses the intrinsic J -coupling of ions in a static magnetic gradient. Dephasing of the interaction is suppressed by means of continuous dynamical decoupling using pairs of microwave fields. The gate is virtually insensitive to common amplitude noise of the microwave fields and enables high fidelities despite qubit frequency fluctuations, while the J -coupling interaction's inherent robustness to motional decoherence is retained. Errors far below the fault-tolerant threshold can be achieved at high initial temperatures, negating the requirement of sideband cooling below the Doppler temperature. By adjusting the powers of the continuous microwave fields, the J -coupling interaction can be tuned and can be used to implement parallel entangling gates within an ion chain.