抗噪声量子计算实验研究

Quantum computations promise great advantages and prospects that the classical computation cannot achieve. However, noise could be one of the main obstacles to realizing the pratical quantum compuaters. Thus the study of the robust quantum computations, which is robust in the presence of noise, attracts worldwide attentations. Herein, we focus on the solid-state quantum computations based on spins, where electron and nuclear spins are taken as qubits. The control of the qubits are achieved via electron (nuclear) spin magnetic resonance techniques. With our previous expriences of dynamical decoupling and shaped pulses techniques, we can experimentally study the robust quantum computations. .To suppress the noises, which deteriorate the performance of quantum computations, is of great challange. The noise can be induced by the inevitable interactions between the qubits and the environment. This effect is well known as decoherence. We take dynamical decoupling techniques as a powerful weapon to fight against the decoherence. On the other hand, the imperfect operations on qubits, such as nonideal rectangle microwave or radio-frequency pulses, will introduce additional noise. To overcome this type of noise, we utilize shaped pulses whose amplitudes and phases are modulated within the qubits' coherent times. The performance of the shaped pulses will first be evualated numerically by simulations and then be tested experimentally. Furthermore, the technique to simultaneously overcome both mentioned noises will be of more importance. We will exploit both advantages of dynamical decoupling and shaped pulses to realize a robust quantum computation. Our reseach will lay the foundation of the futur pratical quantum computations.

量子计算具备经典计算所无法比拟的优势和前景，然而噪声会严重制约和影响量子计算的性能。因此，研究如何抵抗噪声，开展抗噪声量子计算研究成为国际上量子计算研究的重点和热点之一。本项目聚焦于基于自旋的固态量子计算方案，以磁共振技术为量子操纵和调控手段，结合项目组多年来发展的动力学解耦控制技术和成型脉冲技术，开展抗噪声量子计算实验研究。一方面，量子系统与环境之间存在不可避免的相互作用，这将导致量子信息发生向环境不可逆转的耗散。针对这类环境的噪声，本项目组采用动力学解耦技术来抑制并抵消环境的影响。另一方面，由于对量子系统的操控本身不完美，会带来额外的噪声。对于这类噪声，本项目拟采用组合脉冲以及成型脉冲技术来克服其影响。本项目的研究，为实现高保真度量子计算打下坚实基础。

量子计算具备经典计算所无法比拟的优势和前景，然而噪声会严重制约和影响量子计算的性能。因此，研究如何抵抗噪声，开展抗噪声量子计算研究成为国际上量子计算研究的重点和热点之一。本项目聚焦于基于自旋的固态量子计算方案，以磁共振技术为量子操纵和调控手段，结合项目组多年来发展的动力学解耦控制技术和成型脉冲技术，开展抗噪声量子计算实验研究。.通过本项目的研究，我们解决了制约固态自旋量子精确操控的一系列关键问题，实现了动力学解耦量子逻辑门、实现了国际最高指标的固态自旋量子控制精度、实现了时间最优量子控制等一系列工作，并且将相关技术用于量子精密测量等前沿研究，取得了一系列重要成果。