When Symmetry Suppresses Magic
arXiv:2609.38319
Can a physically motivated symmetry make many-body magic analytically solvable, if so at what cost? We answer this question for pairwise parity symmetry, which gives rise to X-states. We show that their magic can be calculated analytically, but is limited to at most a single qubit’s worth, regardless of system size. Our results also provide a universal, computable lower bound for certifying magic in general quantum states. Finally, we determine the temperature below which magic emerges at thermal equilibrium in parity-symmetric systems.
Hi, I’m Alê, a Brazilian physicist working at the Technical University of Denmark.
Recently, my work has been all about witnessing and quantifying quantum features. This has led me to quantum information theory, with a particular emphasis on quantum thermodynamics, where I’m interested in optimal ways of detecting or generating quantum features. More recently, my attention has turned to magic (nonstabiliserness). Not too far from that, I’m also very interested in nonlocality, especially in prepare-and-measure scenarios.
News
Happy to have received IOP Trusted Reviewer status in recognition of my peer-review work.
Spent the week in Belgium as a jury member for Serge Deside’s PhD defense and visiting Nicolas Cerf. I also gave a talk on heat as a witness of quantum properties. A great week of physics and discussions!
One of my favourite projects I’ve worked on appeared on arXiv today: When Symmetry Suppresses Magic, with the amazings Jake Xuereb, Rafael A. Macêdo, Jonatan Bohr Brask, and Rafael Chaves. I was trying to solve a completely different problem, somehow ended up with this one, and got obsessed with it.
My good collaborator Santiago Zamora has just put out our new work The logical set of Gaussian states under the stabilizer subsystem decomposition, together with Kaustav Chatterjee, Ulrik Lund Andersen, Thiago Lucena de Macedo Guedes, Jonatan Bohr Brask, and Rafael Chaves. This project started when Santiago was visiting us. A very cool idea and a lot of fun calculations!
Spent three days visiting the great Martí Perarnau-Llobet and his group at Universitat Autònoma de Barcelona (UAB). I also gave a talk on trading athermality for nonstabilizerness. Great discussions and a very fun visit!
Today Jake fired up arXiv with Anomalous Local Heat Capacity and Bipartite Entanglement. One of the nicest projects I’ve worked on, born from a superexponential number of endless meetings with curly qubit.
Another one out! Randomness Certification and Trade-offs in the Prepare-and-Broadcast Scenario, with Tailan S. Sarubi, Moisés Alves, Vinícius F. Alves, Santiago Zamora, Diogo H. G. Duarte, and Rafael Chaves.
Had a great time at the International Conference for Young Quantum Information Scientists (YQIS) in Vienna, where I presented our work on trading athermality for nonstabilizerness. Leo was with us!
Back in Brazil for the Quantum Thermodynamics Conference, where I gave an invited talk on heat as a witness of quantum properties.
Just learned that I got a Juan de la Cierva Grant! Very happy about this one!
Super cool work on arXiv! The Prepare and Broadcast Scenario, with Tailan S. Sarubi, Moisés Alves, Santiago Zamora, Vinícius F. Alves, and Rafael Chaves. A new playground for thinking about quantum correlations in one of the simplest communication settings.
Spent a few days visiting Steve Campbell @ University College Dublin and John Goold @ Trinity College Dublin, where I gave a seminar on heat as a witness of quantum properties. Definitely one of the nicest scientific trips I’ve had!
Publications
Hover a poster for the full title and abstract.
