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Pietro Richelli

Publications and source records attributed to Pietro Richelli.

2 recordsLinked to original sources

Strong Zero Modes in Supersymmetry-Inspired Quantum Circuits

We investigate discrete dynamics in quantum circuits with gates corresponding to the S-matrix of a supersymmetric 1+1D quantum field theory. We show that for a brick-wall configuration such circuits support both localized and delocalized dynamically conserved operators known as strong zero modes (SZM), the number of which depends on the parameter regime. We demonstrate that, while some of the SZM remain localized at boundaries, other SZM propagate ballistically, guided by a choice of circuit parameters. Such propagation can be explained by a strong Dzyaloshinskii Moriya term appearing in the dynamics. We describe how to exploit propagating SZM for quantum information transport and discuss the robustness to various types of noise.

quant-ph

Brick Wall Quantum Circuits with Global Fermionic Symmetry

We study brick wall quantum circuits enjoying a global fermionic symmetry. The constituent 2-qubit gate, and its fermionic symmetry, derive from a 2-particle scattering matrix in integrable, supersymmetric quantum field theory in 1+1 dimensions. Our 2-qubit gate, as a function of three free parameters, is of so-called free fermionic or matchgate form, allowing us to derive the spectral structure of both the brick wall unitary $U_F$ and its, non-trivial, hamiltonian limit $H_{\gamma}$ in closed form. We find that the fermionic symmetry pins $H_{\gamma}$ to a surface of critical points, whereas breaking that symmetry leads to non-trivial topological phases. We briefly explore quench dynamics for this class of circuits.

quant-ph