Quantum computation leverages the use of quantumly-controlled conditionals in order to achieve computational advantage. However, since the different branches in the conditional may operate on the same qubits, a typical approach to compilation involves performing the branches sequentially, which can easily lead to an exponential blowup of the program complexity. We introduce and study a compilation technique for avoiding branch sequentialization in a language that is sound and complete for quantum polynomial time, improving on previously existing polynomialsize bounds and showing the existence of techniques that preserve the intuitive complexity of the program.

翻译：量子计算通过利用量子控制的条件分支来实现计算优势。然而，由于条件分支中的不同路径可能操作相同的量子比特，典型的编译方法需要按顺序执行这些分支，这极易导致程序复杂度的指数级膨胀。本文提出并研究了一种编译技术，用于在一种对量子多项式时间具有可靠性与完备性的语言中避免分支顺序化。该技术改进了先前存在的多项式规模界限，并证明了存在能够保持程序直观复杂度的编译方法。