In this talk I introduce a phenomenon of enhancement of quantum memory storage capacity that is taking place in a wide class of systems with high occupancy of cold bosons at criticality. The S-matrix formulation shows that black holes are prominent members of this category. From particle physicists perspective a black hole is describable as a critical state of maximal memory storage capacity of soft gravitons at an extremely high occupation number. The same is true about a de Sitter type Universe. Both systems carry a maximal amount of quantum information that is protected against the standard semi-classical evolution. This leads to some important consequences. In particular, the primordial quantum memory pattern carried by the de Sitter Hubble patch from which our Universe evolved as a result of cosmic inflation was not erased by the latter process and is of observational importance. This opens up a conceptually new opportunity of catching the glimpses of the Universes's primordial quantum hair. The universal nature of the enhanced memory phenomenon allows to study and simulate black hole and de Sitter type quantum information storage and processing in laboratory systems with cold bosons.
Axion electrodynamics was originally motivated by the so called CP violation in high-energy physics. Since nearly one decade it became also important in the context of the electromagnetic response of topological materials. In this talk I will discuss aspects of axion electrodynamics in the context of vortices in superconductors proximate to topological insulators. I will also discuss quantum fluctuations of vortex lines in this context, including duality and renormalization group aspects.
Shape constrains and enables function across scales. But how can we design and control shape, i.e. solve the basic inverse problems in physical geometry. I will discuss our work in this area that focuses on 3 different paradigms: (i) using origami to fold flat sheets into curved surfaces, (ii) using kirigami to reshape planar domains and tile arbitrary surfaces, (iii) using biomimetic 3D and 4D printing combined with designer metrics that allow us to “grow” a flat surface into a complex 3D shape such as a flower or a face.
Recently, number of works has been emphasising on the role of a rather unconventional global symmetry of quantum field theories, ranging from QCD to SPT phases. I will start by discussing roles of the so-called higher-form global symmetry (associating with line/defect operators) in various QFTs. More interestingly, the higher-form symmetry and ordinary global symmetry can be mixed together in a certain way to form a larger structure called higher-group. I will discuss the systems where this higher-group global symmetry appears, in particular when gauging a subgroup of a QFT with anomaly. The main focus of this talk will be about the hydrodynamic description of the higher-form and higher-group global symmetry and their observable consequences.
The description of open quantum systems is amenable to a broad range of theoretical tools. Those include the derivation of different types of reduced master equations from specific microscopic modes and under the validity of physically motivated assumptions. A conceptually different approach relies on the formulation of phenomenological master equations, which in the more abstract formalism yield to the description of open system dynamics in terms of quantum channels. Using quantum metrology as a thread, I will illustrate the interrelation and complementarity of different formalisms to describe open quantum systems in order to provide a comprehensive approach to determining fundamental limits to the ultimate achievable precision in metrology and sensing.