一句话：提出 Qompress，将两个 qubit 压缩编码到一个四态 ququart，并用最优控制门减少量子通信开销。
量子计算硬件处于资源受限阶段，门保真度、相干时间与计算单元数量有限。现有设备多采用二元 qubit，每个物理单元只利用 0/1 两态，但许多平台可通过操控访问更多能级。本文提出 Qompress，通过压缩方案自动将两个 qubit 编码进一个四态 ququart，并利用部分基数与混合基数操作减少量子通信。作者使用量子最优控制设计概念验证门，使这些编码 qubit 上能够完整复现标准 qubit 计算，从而在证明编码计算可行性的同时降低通信开销。
Quantum computing is in an era of limited resources. Current hardware lacks high fidelity gates, long coherence times, and the number of computational units required to perform meaningful computation. Contemporary quantum devices typically use a binary system, where each qubit exists in a superposition of the 0 and 1 states. However, it is often possible to access the 2 or even 3 states in the same physical unit by manipulating the system in different ways. In this work, we consider automatically encoding two qubits into one four-state ququart via a compression scheme. We use quantum optimal control to design efficient proof-of-concept gates that fully replicate standard qubit computation on these encoded qubits.
@inproceedings{paperbot10027,
title = {Qompress: Efficient Compilation for Ququarts Exploiting Partial and Mixed Radix Operations for Communication Reduction},
author = {Andrew Litteken and Lennart Maximilian Seifert and Jason Chadwick and Natalia Nottingham and Frederic T. Chong and Jonathan M. Baker},
booktitle = {ASPLOS},
year = {2023},
doi = {10.1145/3575693.3575726}
}