State Preparation Boosters for Early Fault-Tolerant Quantum Computation

• DOI: 10.22331/q-2022-10-06-829
• Publication Date: 2022-10-10T12:02:16Z
• Authors: Guoming Wang; Sukin Sim; Peter D. Johnson
• Keywords: Booster (rocketry)

Quantum computing is believed to be particularly useful for the simulation of chemistry and materials, among various applications. In recent years, there have been significant advancements in development near-term quantum algorithms simulation, including VQE many its variants. However, such useful, they need overcome several critical barriers inability prepare high-quality approximations ground state. Current challenges state preparation, barren plateaus high-dimensionality optimization landscape, make preparation through ansatz unreliable. this work, we introduce method boosting, which uses a limited-depth circuit reliably increase overlap with This circuit, call booster, can used augment an from or as stand-alone method. The booster converts depth into controllable manner. We numerically demonstrate capabilities boosters by simulating performance particular type namely Gaussian preparing <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>N</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> molecular system. Beyond direct objective, algorithms, phase estimation, rely on subroutine. Therefore, foresee boosting similar methods becoming essential algorithmic components field transitions using early fault-tolerant computers.