Outrunning decoherence: Fast state preparation to increase the accuracy of near-term variational quantum computing

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Nick Mayhall
October 5, 2020
4:10PM - 5:00PM
Location
https://osu.zoom.us/j/94054048207?pwd=TUVHSDRvV3F6dGI3S3JSSE1aREhoZz09

Date Range
Add to Calendar 2020-10-05 16:10:00 2020-10-05 17:00:00 Outrunning decoherence: Fast state preparation to increase the accuracy of near-term variational quantum computing Speaker:  Nick Mayhall, Virginia Tech (https://nmayhall-vt.github.io/group_website)   Title: Outrunning decoherence: Fast state preparation to increase the accuracy of near-term variational quantum computing   Abstract: Quantum simulation of chemical systems is one of the most promising near-term applications of quantum computers. Although fully error corrected devices would enable “approximation-free” algorithms like quantum phase estimation to provide arbitrarily accurate calculations of strongly correlated molecules, significant practical and theoretical challenges exist, making hardware realization not likely in the near future. In contrast, the Variational Quantum Eigensolver (VQE) is more robust to noise and errors, and has been experimentally demonstrated on current NISQ devices. Unfortunately, this increased robustness comes at the cost of the introduction of approximations in the form of an ansatz. This defines the key tradeoff with VQE: longer circuits permit higher accuracy, while shorter circuits minimize problems from device noise and errors. Our work focuses on designing ansatze which maximizes the accuracy, while minimizing the circuit complexity. In this talk, I will give a relatively simple introduction to quantum computing, discuss how it relates to theoretical chemistry, and present two distinct families of quantum algorithms that our collaborative team have recently designed, demonstrating that they make significant improvements over the existing approaches.   Zoom seminar, Monday 10/5 @ 16:10  https://osu.zoom.us/j/94054048207?pwd=TUVHSDRvV3F6dGI3S3JSSE1aREhoZz09                              Meeting ID: 940 5404 8207;  Password: 114557 https://osu.zoom.us/j/94054048207?pwd=TUVHSDRvV3F6dGI3S3JSSE1aREhoZz09 Institute for Optical Science spectroscopy@osu.edu America/New_York public
Description

Speaker:  Nick Mayhall, Virginia Tech

(https://nmayhall-vt.github.io/group_website)

 

Title: Outrunning decoherence: Fast state preparation to increase the accuracy of near-term variational quantum computing

 

Abstract: Quantum simulation of chemical systems is one of the most promising near-term applications of quantum computers. Although fully error corrected devices would enable “approximation-free” algorithms like quantum phase estimation to provide arbitrarily accurate calculations of strongly correlated molecules, significant practical and theoretical challenges exist, making hardware realization not likely in the near future. In contrast, the Variational Quantum Eigensolver (VQE) is more robust to noise and errors, and has been experimentally demonstrated on current NISQ devices. Unfortunately, this increased robustness comes at the cost of the introduction of approximations in the form of an ansatz. This defines the key tradeoff with VQE: longer circuits permit higher accuracy, while shorter circuits minimize problems from device noise and errors. Our work focuses on designing ansatze which maximizes the accuracy, while minimizing the circuit complexity. In this talk, I will give a relatively simple introduction to quantum computing, discuss how it relates to theoretical chemistry, and present two distinct families of quantum algorithms that our collaborative team have recently designed, demonstrating that they make significant improvements over the existing approaches.

 

Zoom seminar, Monday 10/5 @ 16:10 

https://osu.zoom.us/j/94054048207?pwd=TUVHSDRvV3F6dGI3S3JSSE1aREhoZz09                             

Meeting ID: 940 5404 8207;  Password: 114557