Robust 2-Qubit Gates in a Linear Ion Crystal Using a Frequency-Modulated Driving Force.


In an ion trap quantum computer, collective motional modes are used to entangle two or more qubits in order to execute multiqubit logical gates. Any residual entanglement between the internal and motional states of the ions results in loss of fidelity, especially when there are many spectator ions in the crystal. We propose using a frequency-modulated driving force to minimize such errors. In simulation, we obtained an optimized frequency-modulated 2-qubit gate that can suppress errors to less than 0.01% and is robust against frequency drifts over ±1  kHz. Experimentally, we have obtained a 2-qubit gate fidelity of 98.3(4)%, a state-of-the-art result for 2-qubit gates with five ions.





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Publication Info

Leung, Pak Hong, Kevin A Landsman, Caroline Figgatt, Norbert M Linke, Christopher Monroe and Kenneth R Brown (2018). Robust 2-Qubit Gates in a Linear Ion Crystal Using a Frequency-Modulated Driving Force. Physical review letters, 120(2). p. 020501. 10.1103/physrevlett.120.020501 Retrieved from

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Norbert Matthias Linke

Assistant Professor of Physics

Kenneth R Brown

Michael J. Fitzpatrick Distinguished Professor of Engineering

Prof. Brown's research interest is the control of quantum systems for both understanding the natural world and developing new technologies. His current research areas are the development of robust quantum computers and the study of molecular properties at cold and ultracold temperatures.

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