Robustly Your Operations

Quantum systems are delicate, and the name of the game is performance. In quantum logic gates, one would like to be as precise as possible in the parameters of the gate (e.g. duration, deriving laser intensity, and more...), in order to have the best fidelity (or quality) of operations. Here, we show that our spectral engineering and coherent control methods could be used to ease on this matter and obtain more robust operations.

Robust gates against errors in gate time

In standard 2-qubit Molmer-Sorensen gates we operate the gate by driving a bi-chromaitc laser drive to a pair of ions. The drive incudes motion that results in a geometric phase accunulated between the 2 qubits as time goes on, until a certain point where we stop the laser drive and the system returns to a stationary state again. Errors in the timing of the laser drive a reduce the fidelity of the operation. By adding some more spectral components to the driving laser field, we can take in accuracies or noise sources affecting this timing, and essentially have a flatter response around the optimal gate time, thereby obtaining less sensitivity to errors in this parameters. We can perform this robustification also with respect to other sources of noise or error resulting in fidelity reductions.

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