In an ion trap quantum computer, collective motional modes are used to
entangle two or more qubits in order to execute multi-qubit logical gates. Any
residual entanglement between the internal and motional states of the ions will
result in decoherence errors, especially when there are many spectator ions in
the crystal. We propose using a frequency-modulated (FM) driving force to
minimize such errors and implement it experimentally. In simulation, we
obtained an optimized FM gate that can suppress decoherence to less than
$10^-4$ and is robust against a frequency drift of more than $\pm$1 kHz. The
two-qubit gate was tested in a five-qubit trapped ion crystal, with $98.3(4)\%$
fidelity for a Mølmer-Sørensen entangling gate and $98.6(7)\%$ for a
controlled-not (CNOT) gate. We also show an optimized FM two-qubit gate for 17
ions, proving the scalability of our method.
%0 Generic
%1 leung2017robust
%A Leung, Pak Hong
%A Landsman, Kevin A.
%A Figgatt, Caroline
%A Linke, Norbert M.
%A Monroe, Christopher
%A Brown, Kenneth R.
%D 2017
%K experiment gates ions
%T Robust two-qubit gates in a linear ion crystal using a
frequency-modulated driving force
%U http://arxiv.org/abs/1708.08039
%X In an ion trap quantum computer, collective motional modes are used to
entangle two or more qubits in order to execute multi-qubit logical gates. Any
residual entanglement between the internal and motional states of the ions will
result in decoherence errors, especially when there are many spectator ions in
the crystal. We propose using a frequency-modulated (FM) driving force to
minimize such errors and implement it experimentally. In simulation, we
obtained an optimized FM gate that can suppress decoherence to less than
$10^-4$ and is robust against a frequency drift of more than $\pm$1 kHz. The
two-qubit gate was tested in a five-qubit trapped ion crystal, with $98.3(4)\%$
fidelity for a Mølmer-Sørensen entangling gate and $98.6(7)\%$ for a
controlled-not (CNOT) gate. We also show an optimized FM two-qubit gate for 17
ions, proving the scalability of our method.
@misc{leung2017robust,
abstract = {In an ion trap quantum computer, collective motional modes are used to
entangle two or more qubits in order to execute multi-qubit logical gates. Any
residual entanglement between the internal and motional states of the ions will
result in decoherence errors, especially when there are many spectator ions in
the crystal. We propose using a frequency-modulated (FM) driving force to
minimize such errors and implement it experimentally. In simulation, we
obtained an optimized FM gate that can suppress decoherence to less than
$10^{-4}$ and is robust against a frequency drift of more than $\pm$1 kHz. The
two-qubit gate was tested in a five-qubit trapped ion crystal, with $98.3(4)\%$
fidelity for a M{\o}lmer-S{\o}rensen entangling gate and $98.6(7)\%$ for a
controlled-not (CNOT) gate. We also show an optimized FM two-qubit gate for 17
ions, proving the scalability of our method.},
added-at = {2017-08-30T14:54:46.000+0200},
author = {Leung, Pak Hong and Landsman, Kevin A. and Figgatt, Caroline and Linke, Norbert M. and Monroe, Christopher and Brown, Kenneth R.},
biburl = {https://www.bibsonomy.org/bibtex/2a7e65db1b23437a0b8d669b98a618b31/marschu},
interhash = {0228afe4a6a20a59bbf13a50b18c9720},
intrahash = {a7e65db1b23437a0b8d669b98a618b31},
keywords = {experiment gates ions},
note = {cite arxiv:1708.08039},
timestamp = {2017-08-30T14:54:46.000+0200},
title = {Robust two-qubit gates in a linear ion crystal using a
frequency-modulated driving force},
url = {http://arxiv.org/abs/1708.08039},
year = 2017
}