Quantum Process Tomography

Mário Ziman

Ze Wu, S. Li, Wenqiang Zheng +2 more

The essential tool to characterize dynamics of an open quantum system is quantum process tomography (QPT). Although standard QPT methods are hard to be scalable, simplified QPT approach is available if we have the prior knowledge that the system Hamiltonian commutes with the system-environment interaction Hamiltonian. Using a nuclear magnetic resonance (NMR) quantum simulator, we experimentally simulate dephasing channels to demonstrate the simplified QPT as well as the standard QPT method as a comparison. The experimental results agree well with our predictions which confirm the validity and better efficiency of the simplified QPT.

Kavan Kishore Modi, Cesar Rodriguez, Aik-meng Kuah +2 more

Péter Wittek

Lynden K. Shalm, Morgan W. Mitchell, Aephraim M. Steinberg

Quantum process tomography is often cited as providing all the information that can be known about a given quantum process. In this paper we have shown that even if two processes appear identical under process tomography, it is possible to distinguish them using an interferometric setup. Using this setup, it is possible to gain more information about a process than just tomography provides.

Xiaohua Wu, Ke Xu