Quantum Computing Seminar: Candidate for a passively-protected quantum memory in two dimensions

Speaker: Alexey Gorshkov, NIST

Title: Candidate for a passively-protected quantum memory in two dimensions

Abstract:
An interesting problem in the field of quantum error correction involves finding a physical system that hosts a "passively-protected quantum memory,'' defined as an encoded qubit coupled to an environment that naturally wants to correct errors. To date, a quantum memory stable against finite-temperature effects is only known in four spatial dimensions or higher. Here, we take a different approach to realize a stable quantum memory by relying on a driven-dissipative environment. We propose a new model which appears to passively correct against both bit-flip and phase-flip errors in two dimensions: A square lattice composed of photonic "cat qubits'' coupled via dissipative terms which tend to fix errors locally. Inspired by the presence of two distinct Z_2-symmetry-broken phases, our scheme relies on Ising-like dissipators to protect against bit flips and on a driven-dissipative photonic environment to protect against phase flips.

Time:  Monday, October 3, 2022, 12:30pm – 1:30pm

Place:  Exploratory Hall, room 3301

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