Special Quantum Matter Seminar

The preparation of quantum states with long-range correlations and topological entanglement is a key objective for quantum simulators and processors. A common approach is the Sequential Quantum Circuit, which applies local unitary transformations to sub-regions of a system sequentially with linear depth. An alternative strategy, the measurement and feedback (MF) circuit, avoids high-depth circuits by using finite-depth unitaries, measurements, and outcome-dependent feedback to prepare states in constant depth.

In this talk, I show how these two methods—sequential circuits and MF protocols—are unified through spacetime duality. This framework interprets nonlocal operators and observables in MF circuits as autocorrelators in sequential circuits. The duality also has broader implications, including insights into non-invertible symmetries in quantum circuits and the interplay between unitary and measurement errors in quantum computation.