Hsi-Sheng Goan - Department of Physics and Center for Quantum Science and Engineering, National Taiwan University, Taipei
An essential prerequisite for quantum information processing is precise coherent control of the dynamics of quantum systems or quantum bits (qubits). Most of the control sequences implemented in quantum experiments are developed and designed based on the assumption of having ideal (closed) quantum coherent systems. However, almost every quantum system interacts inevitably with its surrounding environment resulting in decoherence and dissipation of the quantum system. We have applied the quantum optimal control theory to construct fast and high-fidelity quantum gates taking into account decoherence from dissipative environment for non-Markovian open quantum systems [1,2] and for various promising physical quantum systems [3-5]. Recently, we have developed a systematic method to find pulses for quantum gate operations robust against both low and high-frequency (comparable to the qubit transition frequency) stochastic time-varying noise [6]. Our method that includes detailed information of stochastic time-varying noise in the cost function for optimization can be applied to different system models and noise models. Here we applied this method to construct robust single-qubit and two-qubit gates for quantum-dot spin qubits in purified silicon with fidelity enabling large-scale fault-tolerant quantum computation.
References
[1] B. Hwang and H.-S. Goan, Phys. Rev A 85, 032321 (2012).
[2] J.-S. Tai, K.-T. Lin and H.-S. Goan, Phys. Rev A 89, 062310 (2014).
[3] D.-B. Tsai, P.-W. Chen and H.-S. Goan, Phys. Rev. A 79, 060306 (R) (2009).
[4] Y. Chou, S.-Y. Huang and H.-S. Goan, Phys. Rev A 91, 052315 (2015).
[5] S.-Y. Huang and H.-S. Goan, Phys. Rev A 90, 012318 (2014).
[6] C.-H. Huang and H.-S. Goan, Phys. Rev A 95, 062325 (2017).