Entanglement Transitions in Unitary Circuit Games

Add to your list(s) Download to your calendar using vCal

• Adam Smith, University of Nottingham
• Thursday 26 October 2023, 13:15-14:30
• Theory Library.

If you have a question about this talk, please contact Dr Hannah Price.

Repeated projective measurements in unitary circuits can lead to an entanglement phase transition as the measurement rate is tuned. In this work, we consider a different setting in which the projective measurements are replaced by dynamically chosen unitary gates that minimize the entanglement. This can be seen as a one-dimensional unitary circuit game in which two players get to place unitary gates on randomly assigned bonds at different rates: The “entangler” applies a random local unitary gate with the aim of generating extensive (volume law) entanglement. The “disentangler”, based on limited knowledge about the state, chooses a unitary gate to reduce the entanglement entropy on the assigned bond with the goal of limiting to only finite (area law) entanglement. In order to elucidate the resulting entanglement dynamics, we consider three different scenarios: (i) a classical discrete height model, (ii) a Clifford circuit, and (iii) a general U(4) unitary circuit. We find that both the classical and Clifford circuit models exhibit phase transitions as a function of the rate that the disentangler places a gate, which have similar properties that can be understood through a connection to the stochastic Fredkin chain. In contrast, the ``entangler’’ always wins when using Haar random unitary gates and we observe extensive, volume law entanglement for all non-zero rates of entangling.

Reference: arXiv:2304.12965

This talk is part of the Theoretical Physics Seminars series.

This talk is included in these lists:

• Bham Talks
• Theoretical Physics Seminars
• Theory Library
• What's on in Physics?

Note that ex-directory lists are not shown.