# Hamburg Prize for Theoretical Physics

In order to strengthen and promotephoto science research in Hamburg and to increase international visibility, the prestigious “Hamburger Preis für theoretische Physik” was established in 2010 by the state-funded Cluster of Excellence “Frontiers in Quantum Photon Science” at the University of Hamburg, which was also supported by the Joachim Herz Foundation.

Starting in 2013, the prize was awarded by the Hamburg Centre for Ultrafast Imaging (CUI) and the Joachim Herz Foundation and comprised an award certificate as well as and a personal prize money of € 40.000 in personal prize money. As of 2018, the prizeisawarded together with the Joachim Herz Foundation and the Wolfgang Pauli Centre (WPC) of the Universität Hamburg and DESY as well as with the two clusters of excellence of the Universität Hamburg "CUI: Advanced Imaging of Matter" and “Quantum Universe”. It now involves all areas of theoretical physics and is endowed with € 137.036 in total – a figure that plays on Sommerfeld’s fine-structure constant, - and is thereby one of the most valuable German prizes for physics. The prize winner is expected to interact with the cluster´s research groups, especially with its young researchers (e.g. via lectures and seminars) during one or more visits to Hamburg.

Nominations may be submitted by Hamburg physics institutes, the Board of the Deutsche Physikalische Gesellschaft e. V. (DPG), as well as former awardees and jury members. The award ceremony takes place an international theoretical physics conference in Hamburg in November.

Previous recipients of the award are Prof. Maciej Lewenstein (2010), Prof. Peter Zoller (2011), Prof. Shaul Mukamel (2012), Prof. Chris H. Greene (2013), Prof. Antoine Georges (2014), Prof. Ignacio Cirac (2015), Prof. Mikhail Katsnelson (2016), Prof. Andrew Millis (2017), Prof. Hirosi Ooguri (2018), Prof. Matthias Troyer (2019), Prof. Valery Rubakov (2020) and Prof. Eugene Demler (2021).

## Eugene Demler

The Russian-American researcher Eugene Demler is to receive the Hamburg Prize for Theoretical Physics 2021. Demler, who has been a physics professor at Harvard University in the USA since 2001 and will join ETH (Zurich) faculty in the Fall of 2021, works on understanding strongly correlated quantum matter from electrons in solids to dilute atomic gases to photons. His work has had a profound impact on diverse areas such as magnetism and superconductivity, many-body physics with ultracold atoms in optical lattices, nonlinear quantum optics, and pump and probe experiments in solids. The prize will be awarded to Demler in November 2021 in Hamburg.

### Towards a better understanding of materials with quantum simulation

Demler is a world-renowned expert in theoretical quantum physics. Theoretical quantum physics describes how electrons, atoms and other miniscule objects behave. Among other things, Demler’s work was instrumental to the development of the field of quantum simulators based on ultracold atoms. When trying to understand complex materials, condensed matter theorists introduce simplified models, analyze them, and try to relate their results to experimentally measured properties of materials. However, even basic models are difficult to solve accurately when they involve strong interactions between particles. When theoretical results disagree with experiments, it is not clear whether this comes from not being able to solve the model accurately or from the model lacking some important features. Quantum simulators resolve this problem by creating experimental systems that emulate fundamental models of condensed matter physics. In particular, cold atom simulators use atoms arranged into periodic structures with laser beams to create artificial crystals.

Experiments done on cold atom simulators will not only allow researchers to understand the properties of paradigmatic models but will also elucidate what they are missing for describing condensed matter systems. Experiments done on cold atom simulators have already delivered new insights into the properties of materials that arise from the complex interaction of thousands of particles that obey the laws of quantum mechanics. These include quantum magnets and topological insulators, as well as superconductors, which are materials that allow resistance-free transmission of electricity.

## Valery Rubakov

In recent years, research teams around the world have gained important insights into the origin of the universe. They often relied on the work of Valery Rubakov. The Russian physicist will receive this year’s Hamburg Prize for Theoretical Physics. Rubakov is chief researcher at the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow and Professor at M.V. Lomonosov Moscow State University.

The question of what we and the world around us are made of has always driven humankind. Our matter is built up of atoms, which again consist of protons, neutrons, and electrons. In the classical standard model of particle physics which describes all known elementary particles and their fundamental forces with the strong and weak interaction and electromagnetism, the proton is considered as stable. Valery Rubakov challenged this assumption and developed the theory of catalysis of proton decay by magnetic monopoles, the so-called Callan-Rubakov effect. This effect suggests that a magnetic monopole would cause a decay of protons, the basic building blocks of our matter, leaving an observable footprint in the form of lighter particles such as positrons, photons, and neutrinos. Magnetic monopoles must have been created shortly after the Big Bang and theoretically still occur sporadically today.

Rubakov also provided important explanatory models for the origin of matter in the universe and disappearance of antimatter. Antimatter is a kind of mirror image of our matter. For every particle there is an antiparticle with opposite charge. When particles and antiparticles meet, they extinguish each other by emitting a flash of energy. Since our universe consists of matter, an asymmetric process must have caused an imbalance between matter and antimatter shortly after the Big Bang in the early phase of our universe. The violation of the baryon number in the standard model, which Rubakov published as early as the mid-1980s, provides an important theoretical explanation for the origin of this imbalance and is still one of the most challenging questions and a field of active research today. Today, numerous experiments in particle accelerators aim to study the properties of antimatter and thus to find indications for the origin of our universe and its expansion, which continues until today.

# Matthias Troyer

This year’s Hamburg Prize for Theoretical Physics will be presented to Austrian Matthias Troyer, a professor at ETH Zurich and quantum computing researcher at software company Microsoft. He is receiving the prize for his contributions to the development of quantum Monte Carlo algorithms.

Using random numbers, these algorithms can predict how tiny particles will interact within quantum mechanical many-body systems such as atoms and molecules. As a result, Troyer is playing a key role in basic research and the ongoing development of quantum computers and superconductive materials. He is one of just a handful of leading international researchers in this field. The Joachim Herz Stiftung awards the prize in conjunction with the Wolfgang Pauli Centre (WPC) at the University of Hamburg, DESY, and the Cluster of Excellence “CUI: Advanced Imaging of Matter” at the University of Hamburg.

# Hirosi Ooguri

This year’s Hamburg Prize for Theoretical Physics will be awarded to the Japanese scientist Hirosi Ooguri. Ooguri, born in 1962, is a professor at California Institute of Technology (Caltech) in Pasadena (USA). He is one of the world’s leading experts on so-called topological string theory, which addresses mathematical aspects of superstring theory – an important path towards an all-encompassing theory on the nature of our universe. Ooguri will be presented with the award on November 7, 2018 at the Hamburg Planetarium.

Ooguri´s research deals with mathematical superstring theory. Ooguri has succeeded in enabling many physical phenomena to be computed with the aid of string theory. He was able to overcome many of the major mathematical difficulties of string theory. Moreover, Ooguri’s research on the quantum mechanics of black holes continues the research of physicist Stephen Hawking, who died earlier this year.

Ooguri arrived at Caltech in 2000 as a professor for theoretical physics. He is Fred Kavli Professor and Director of the Walter Burke Institute for Theoretical Physics. Moreover, he is a principal investigator of the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo, and has recently been appointed President of the Aspen Center for Physics in Colorado, USA.

Ooguri has received numerous awards. He is a Fellow of the American Academy of Arts and Sciences, to name but one, and has also received the Leonard Eisenbud Prize for Mathematics and Physics from the American Mathematical Society.

# Andrew Millis

This year's Hamburg Prize for Theoretical Physics, jointly awarded by the Joachim Herz Stiftung and The Hamburg Centre for Ultrafast Imaging (CUI), will be given to Andrew Millis, Professor at Columbia University in New York and Associate Director for Physical Sciences at the Simons Foundation.

The prize recognizes, the U.S. physicist for his outstanding research in condensed matter physics, a field focusing on atomic and molecular interactions in solids and liquids. His work enables calculations that predict electronic properties of materials, including electrical conductivity and the tendency to magnetism. He has made landmark discoveries in properties of superconducting materials (which can conduct electric current without losses).

While most superconductors must be cooled to extremely low temperatures to reach lossless conductivity - a time-consuming and expensive process - a few are superconducting at much higher temperatures. Millis' research has enhanced our understanding of these special materials, and his recent work may provide a path to pushing the temperature threshold for superconductivity even higher, perhaps all the way to room temperature.

Millis studied physics at Harvard University and received a PhD from the Massachusetts Institute of Technology in 1986. He then worked as a scientist at Bell Laboratories in New Jersey. In 1996 Millis was appointed professor at the Johns Hopkins University in Baltimore and three years later moved to Rutgers University in New Jersey. In 2001 he joined the physics department at Columbia University, where he served as Department Chair from 2006 - 2009. Since 2011 he has been Associate Director for Physical Sciences at the Simons Foundation, a large U.S. foundation whose mission is to advance mathematics and basic research. Starting Sept 1, 2017 he will also be co-Director of the Center for Computational Quantum Physics at the Simons Foundation's new Flatiron Institute.

# Prof. Katsnelson

Prof. Katsnelson is working on the quantum mechanical many-body theory, the theory of strongly correlated systems, and the quantum theory of magnetism as well as of graphene. Katsnelson is a researcher with an extraordinary broad range of interests. His work on graphene has greatly profited from his versatile expertise and methodology. Graphene has many remarkable characteristics and can be applied to very different fields of science.

Mikhail Katsnelson published his first scientific papers at the age of 17 and started his academic career in the former Soviet Union. After passing the Master of Science examination in Theoretical Physics at the Department of Physics at Ural State University, Sverdlovsk, he received his PhD in Solid State Physics at the Institute of Metal Physics (Sverdlovsk) in 1980 and his DSc in 1985. Seven years later he was appointed to a professorship for Solid State Physics and for Mathematical Physics at Ural State University. In 2004, after spending two years in Sweden as visiting professor at Uppsala University, Radboud University in Nijmegen, Netherlands, appointed him to a professorship. He is head of the group “Theory of Condensed Matter”.

# Prof. Dr. Ignacio Cirac

The recipient of the 2015 “Hamburg Prize for Theoretical Physics” is Prof. Dr. Ignacio Cirac, Director at the Max Planck Institute of Quantum Optics in Garching and head of the Theory Division.

Ignacio Cirac studied theoretical physics at the Universidad Complutense de Madrid where he received his PhD in 1991. He began his career in physics as a “Professor Titular” at the Universidad de Castilla-La Mancha where he stayed until 1996. In 1996 he became a Professor at the department of Theoretical Physics at the University of Innsbruck. Since 2001 he has been Director at the Max Planck Institute of Quantum Optics in Garching and head of the Theory Division.

Prof. Cirac develops methods to describe and control atoms, molecules and photons on the basis of quantum mechanics. His quantum physics models are particularly pioneering for the control and storage of information, which is, for instance, important for the development of quantum computers. Cirac’s methods also make major contributions to other fields like solid state physics, superconductivity and recently even the simulation of models of particle physics.

#### Honors and Awards (selection)

Felix Kuschenitz Preis, Austrian Academy of Sciences, 2001,

Quantum Electronics Prize, European Science Foundation, 2005,

Royal Spanish Prince of Asturias Prize, 2006,

International Quantum Communication Award, 2006, together with Professor Peter Zoller,

Frontiers of Knowledge Award in Basic Sciences, BBVA Foundation, 2009,

Benjamin Franklin Medal, Franklin Institute in Philadelphia, 2009, together with Professor Peter Zoller,

Israeli Wolf Prize and Niels Bohr Medal, 2013,

Honorary Doctor from the University of Zaragoza, 2014,

Honorary Doctor from the University of Valencia as well as the Universitat Politècnica de València, 2015.

# ANTOINE GEORGES

The recipient of the 2014 Hamburg Prize for Theoretical Physics is Prof. Antoine Georges, distinguished Professor at the Collège de France and the École Polytechnique in Paris, as well as the University of Geneva. He receives the prize due to his contributions to condensed matter physics, in particular for the development of novel methods to describe strongly correlated systems.

In 1988 Prof. Georges received his PhD at the École Normale Supérieure. Due to an offer of the Princeton University, Antoine Georges has been working in the USA as a Postdoc from 1989 to 1991. With returning to France in 1991, he deepened his research regarding the condensed matter physics and later on in 2003 directed a research team at the École Polytechnique. Since 2009 he is a Professor of Condensed Matter Physics at the Collège de France. He is also working as a part-time professor at the University of Geneva.

The main focus of Prof. Georges‘ research has been on the physics of materials with strong interactions between electrons, which possess remarkable electronic properties. His contributions deepened our understanding of these materials and our ability to explain, calculate and predict their physical properties.

### HONORS AND AWARDS (SELECTION)

Anatole et Suzanne Abragam Prize, Academie des Sciences, 1991

Prix Dargelos, École Polytechnique (AX), 2004

Condensed Matter Europhysics Prize for “the development and application of Dynamical Mean-Field Theory'', European Physical Society and Agilent Technologies, 2006;

together with Gabriel Kotliar, Walter Metzner, Dieter Vollhardt

Médaille d'Argent du CNRS, CNRS, 2007

Laureate of an ERC-Synergy grant, ERC, 2012;

together with Andrea Cavalleri, Dieter Jaksch and Jean-Marc Triscone.