IQI Weekly Seminar

Abstract: In the first half of the talk, I will present my recent work (https://quantum-journal.org/papers/q-2020-09-11-318/) on simulating 1D noisy RCS with matrix product operators (MPOs). I will demonstrate that, given a fixed non-zero error rate per gate, the MPO entanglement entropy peaks at an optimal circuit depth that depends only on the gate error rate and is bounded by a constant independent of the system size. Thus, above a characteristic system size, the time cost of classical MPO simulation only increases polynomially in the number of qubits. I will also briefly discuss a simple toy model based on erasure channels.

In the second half, I will give an overview of circuit-QED implementation of bosonic quantum error correction (QEC). I will review several key control techniques and discuss experimental realization of "break-even" QEC with cat, binomial, and GKP codes. I will also discuss challenges and possible future directions.