Zhang J, Kyaw Thi Ha, Tong D M, Sjöqvist Erik, Kwek Leong-Chuan
Department of Physics, Shandong University, Jinan 250100, China.
Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore.
Sci Rep. 2015 Dec 21;5:18414. doi: 10.1038/srep18414.
A practical quantum computer must be capable of performing high fidelity quantum gates on a set of quantum bits (qubits). In the presence of noise, the realization of such gates poses daunting challenges. Geometric phases, which possess intrinsic noise-tolerant features, hold the promise for performing robust quantum computation. In particular, quantum holonomies, i.e., non-Abelian geometric phases, naturally lead to universal quantum computation due to their non-commutativity. Although quantum gates based on adiabatic holonomies have already been proposed, the slow evolution eventually compromises qubit coherence and computational power. Here, we propose a general approach to speed up an implementation of adiabatic holonomic gates by using transitionless driving techniques and show how such a universal set of fast geometric quantum gates in a superconducting circuit architecture can be obtained in an all-geometric approach. Compared with standard non-adiabatic holonomic quantum computation, the holonomies obtained in our approach tends asymptotically to those of the adiabatic approach in the long run-time limit and thus might open up a new horizon for realizing a practical quantum computer.
一台实用的量子计算机必须能够对一组量子比特(qubit)执行高保真量子门操作。在存在噪声的情况下,实现此类门操作面临着艰巨的挑战。具有内在抗噪声特性的几何相位,为执行稳健的量子计算带来了希望。特别是量子全同伦,即非阿贝尔几何相位,由于其不可交换性,自然地导致了通用量子计算。尽管基于绝热全同伦的量子门已经被提出,但演化速度慢最终会损害量子比特的相干性和计算能力。在此,我们提出一种通用方法,通过使用无跃迁驱动技术来加速绝热全同门的实现,并展示如何在超导电路架构中以全几何方法获得这样一组通用的快速几何量子门。与标准的非绝热全同伦量子计算相比,我们方法中获得的全同伦在长时间运行极限下渐近地趋于绝热方法的全同伦,因此可能为实现实用的量子计算机开辟新的前景。