Speaker
Description
In a quantum processor, quantum degrees of freedom such as the internal states of trapped atomic ions form a quantum bit of information, or qubit, and can be manipulated by laser beams. To improve the scalability of trapped-ion quantum computing, as well as to implement a broader range of algorithms, individual qubit state manipulation is a necessity. For high fidelity quantum gates, some of the requirements are minimal relative intensity crosstalk on neighbouring ions, a fast switching time (microseconds or better), and high programmability of target addressing, especially when ion spacings are non-uniform. In this talk I will present our recent progress in realizing a large-scale (>30 ions) quantum processor with low crosstalk individual qubit manipulation using a dual acousto-optic deflector (AOD) system. The coherent Raman addressing delivery is enabled by mapping frequencies of the AODs to positions along the ion chain, carefully calibrated by optimizing the AOD output in an intermediate image plane before relaying it to the ions. One of the challenges of this system is mapping both AODs to each ion position with the exact same frequency, so as to not introduce any unwanted detunings. However, these have been mitigated through careful optics simulation and reiterative testing. We will also discuss the implications on the fidelity of quantum gates due to tightly focused laser beams, comparable in size to the extent of the ion's motional spread in space, and a novel mitigation strategy. Our dual AOD system allows for fast, programmable single- and two-qubit quantum gates for a wide range of quantum algorithms -- both digital and analog.
| Keyword-1 | trapped ions |
|---|---|
| Keyword-2 | quantum simulations |