We simulate a zero-temperature pure Z3 Lattice Gauge Theory in 2+1 dimensions by using an iPEPS (Infinite Projected Entangled-Pair State) ansatz for the ground state. Our results are therefore directly valid in the thermodynamic limit. They clearly show two distinct phases separated by a phase transition. We introduce an update strategy that enables plaquette terms and Gauss-law constraints to be applied as sequences of two-body operators. This allows the use of the most up-to-date iPEPS algorithms. From the calculation of spatial Wilson loops we are able to prove the existence of a confined phase. We show that with relatively low computational cost it is possible to reproduce crucial features of gauge theories. We expect that the strategy allows the extension of iPEPS studies to more general LGTs.
Theorists have made a significant stride in the field of quantum computing. Their research addresses a long-standing question: can quantum computers really outperform classical computers in solving complex problems, despite the presence of errors? In a new study focusing on analogue quantum simulators – specialised quantum devices used to mimic physical systems – the researchers could show precisely that.
The theoretical physicist, who is currently being hosted by the MPQ Theory Division, has won a 2024 Starting Grant from the European Research Council. The ERC Starting Grant is the highest award for excellent young scientists in Europe. With this funding, Jad C. Halimeh and his group intend to advance current concepts of quantum simulation, particularly for higher-dimensional gauge theories and their far-from-equilibrium quantum many-body dynamics.
Oriana Diessel completed her doctorate in Richard Schmidt's independent research group. Her theoretical work focusses on two special features of many-body systems: so-called "polarons" and previously unknown phase transitions in light-matter systems. In her work, Oriana Diessel developed models to theoretically describe the two phenomena, thereby providing a further building block for our understanding of quantum many-body theory.
Being elected as a member of the National Academy of Sciences is regarded as one of the most distinguished honours a scientist can receive. While the majority of members hold U.S. citizenship, up to 30 international members are elected annually. NAS members are “charged with providing independent, objective advice on matters related to science and technology”.
Theorists in the research group of Mari Carmen Bañuls at MPQ have come one step closer to understanding the evolution of quantum many body systems over time. In their work, recently published in the specialized journal Physical Review Letters, they formulated an algorithm to simulate the dynamics of quantum systems consisting of many particles out of equilibrium – a notoriously difficult task.