Perfect Wave Transfer in Continuous Quantum Systems

by Per Moosavi (Stockholm University)

Tuesday Dec 10, 2024, 10:30 AM → 12:00 PM Europe/Stockholm

AlbaNova A3:1003 - Styrelserum/KOMKO (AlbaNova Main Building)

The transfer of information from one part of a quantum system to another is fundamental to the understanding and design of quantum-information-processing devices. In the realm of discrete systems, such as spin chains, inhomogeneous networks have been engineered that allow for the perfect transfer of states from one end to the other. In this talk, by contrast, I present recent work on perfect transfer of information in inhomogeneous continuous systems, phrased in terms of wave propagation. A remarkable difference is found between systems that possess conformal symmetry and those that do not. Systems within the first class enjoy perfect wave transfer (PWT), shown in general at least for one-particle excitations. Among the second class, those that exhibit PWT are characterized as solutions to an inverse spectral problem. As a concrete example, we demonstrate how to formulate and solve this inverse problem for a prototypical class of bosonic theories, showing that conformal symmetry is both necessary and sufficient for these theories to enjoy PWT for smoothly varying inhomogeneities. Using bosonization, our continuum results extend to theories with interactions, broadening the scope of perfect information transfer to more general quantum systems.

Based on joint work arXiv:2408.00723 with M. Christandl, G. M. Graf, and S. Sotiriadis.