论文标题
量子多体时间演变运算符到砖墙电路中的最佳压缩
Optimal compression of quantum many-body time evolution operators into brickwall circuits
论文作者
论文摘要
近期量子计算机具有一定程度的破裂，这对于具有深电路的高保真模拟而言是过于敏感的。因此，电路深度的经济使用至关重要。对于量子多体系统的数字量子模拟，通常通过将时间演化运算符分解为仅由两个量子门组成的电路来实现实时演变。为了匹配物理系统的几何形状和量子处理器的CNOT连接性，需要其他交换门。我们表明，除了简单的小猪圈分解可实现的固定门计数外，还可以通过将进化运算符汇编为$ s = 1/2 $ s = 1/2 $ Quantum Heisenberg模型的最佳砖墙电路来获得固定的门数，而当映射到一个尺寸量化的量子处理器时，则可以获得额外的量化剂量。
Near term quantum computers suffer from a degree of decoherence which is prohibitive for high fidelity simulations with deep circuits. An economical use of circuit depth is therefore paramount. For digital quantum simulation of quantum many-body systems, real time evolution is typically achieved by a Trotter decomposition of the time evolution operator into circuits consisting only of two qubit gates. To match the geometry of the physical system and the CNOT connectivity of the quantum processor, additional SWAP gates are needed. We show that optimal fidelity, beyond what is achievable by simple Trotter decompositions for a fixed gate count, can be obtained by compiling the evolution operator into optimal brickwall circuits for the $S = 1/2$ quantum Heisenberg model on chains and ladders, when mapped to one dimensional quantum processors without the need of additional SWAP gates.
