Surviving as a quantum computer in a noisy world

Speaker：

Yihui Quek

Postdoc at MIT/Assistant Professor at EPFL

Time：

Friday, 16:00-17:00

Dec. 27, 2024

Venue：

B627, Shuangqing Complex Building A

Online：

Zoom: 230 432 7880

Password: BIMSA

Title：

Surviving as a quantum computer in a noisy world

Abstract：

Can we compute on small quantum processors? In this talk, I explore the extent to which noise presents a barrier to this goal by quickly drowning out the information in a quantum computation. Noise is a tough adversary: we show that a large class of error mitigation algorithms -- proposals to "undo" the effects of quantum noise through mostly classical post-processing – can never scale up. Then we'll journey into the wild west of non-unital noise, a theoretically understudied class of noise (including damping and photon loss) that predominates on certain physical platforms, and study the task of estimating expectation values in its presence. Having presented some no-go theorems about inference in the presence of noise, I'll attempt to make lemons out of lemonade by turning to cryptography, where I will propose a new hardness conjecture, based on the task of decoding random stabilizer codes.