Abstract: This talk examines incoherent and coherent Pauli error channels in quantum error correction. For incoherent channels, the error threshold is well understood through its mapping to the multicritical Nishimori point of the two-dimensional random-bond Ising model. Coherent channels, by contrast, remain less understood and are an active area of research. In the first part, I compare information-theoretic measures and statistical indicators at the multicritical Nishimori point, and show how the re-entrant phase diagram of the random-bond Ising model can be reinterpreted using decoders at an effective temperature. In the second part, I discuss recent theoretical and numerical results on the thresholds and behavior of coherent error channels.

About the speaker: Dr. Xudong Dai is a postdoctoral researcher in Prof. Xi Dai's group at the Hong Kong University of Science and Technology. He obtained his bachelor's degree from the University of Science and Technology of China and his Ph.D. from the Institute for Advanced Study, Tsinghua University, under the supervision of Prof. Zhong Wang.

Inviter: 孙孝奇 xqsun@iphy.ac.cn