Southwest Quantum Information and Technology

A multi-qubit quantum gate using the Zeno effect

Presenting Author: Philippe Lewalle, University of California Berkeley
Contributing Author(s): Leigh S. Martin, Emmanuel Flurin, Song Zhang, Eliya Blumenthal, Shay Hacohen-Gourgy, Daniel Burgarth, K. Birgitta Whaley

The Zeno effect, in which repeated observation freezes the dynamics of a quantum system, stands as an iconic oddity of quantum mechanics. When a measurement is unable to distinguish between states in a subspace, the dynamics within that subspace can be profoundly altered, leading to non-trivial behavior. Here we show that such a measurement can turn a non-interacting system with only single-qubit control into a two- or multi-qubit entangling gate, which we call a Zeno gate. We derive simple closed-form expressions for the gate fidelity under a number of non-idealities and show that the gate is viable for implementation in circuit and cavity QED systems.

(Session 5 : Thursday from 5:00 pm - 7:00 pm)