Dr Christopher Ballance: Publications

Raman Interactions

Chapter in High-Fidelity Quantum Logic in Ca+, Springer Nature (2017) 15-25

Single-Qubit Gates

Chapter in High-Fidelity Quantum Logic in Ca+, Springer Nature (2017) 87-96

Trapped-Ion Qubits

Chapter in High-Fidelity Quantum Logic in Ca+, Springer Nature (2017) 5-14

Minimally complex ion traps as modules for quantum communication and computing

NEW JOURNAL OF PHYSICS 18 (2016) ARTN 103028

Authors:

R Nigmatullin, CJ Ballance, N de Beaudrap, SC Benjamin

High-Fidelity Trapped-Ion Quantum Logic Using Near-Field Microwaves.

Physical review letters 117:14 (2016) 140501-140501

Authors:

TP Harty, MA Sepiol, DT Allcock, CJ Ballance, JE Tarlton, DM Lucas

Abstract:

We demonstrate a two-qubit logic gate driven by near-field microwaves in a room-temperature microfabricated surface ion trap. We introduce a dynamically decoupled gate method, which stabilizes the qubits against fluctuating energy shifts and avoids the need to null the microwave field. We use the gate to produce a Bell state with fidelity 99.7(1)%, after accounting for state preparation and measurement errors. The gate is applied directly to ^{43}Ca^{+} hyperfine "atomic clock" qubits (coherence time T_{2}^{*}≈50 s) using the oscillating magnetic field gradient produced by an integrated microwave electrode.

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