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.
With the help of high-resolution microscopy, scientists at MPQ successfully observed the transformation of a metal of magnetic polarons into a normal Fermi liquid. Furthermore, the team was able to measure novel correlations that could serve as a basis for theoretical models of strongly-correlated electrons.
Fabian Kugler, former doctoral student in the MPQ Theory Division, receives the Otto-Hahn Medal of the Max Planck Society. The award was established in 1978 and honours up to 30 young scientists per year for outstanding doctoral research.
In his doctoral thesis, Nicola worked on finding new methods for the study of quantum mechanical systems. His research might furthermore help us use quantum physics in other fields such as machine learning.
The award honours internationally renowned scientists from abroad and aims to foster the exchange between Germany and the country of the awardee. From the 22nd of June 2021, Professor Philipp Walther will be a guest scientist at MPQ where he will be working closely with the Theory Division of Ignacio Cirac.