Helmut Ritsch (; born 12 March 1962 in

Innsbruck Innsbruck (; ) is the capital of Tyrol (federal state), Tyrol and the List of cities and towns in Austria, fifth-largest city in Austria. On the Inn (river), River Inn, at its junction with the Wipptal, Wipp Valley, which provides access to the ...

) is an

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

n quantum physicist and a professor of

theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...

at the

University of Innsbruck The University of Innsbruck (; ) is a public research university in Innsbruck, the capital of the Austrian federal state of Tyrol (state), Tyrol, founded on October 15, 1669. It is the largest education facility in the Austrian States of Austria, ...

. Helmut Ritsch's research concerns the fundamental aspects and applications of

quantum optics Quantum optics is a branch of atomic, molecular, and optical physics and quantum chemistry that studies the behavior of photons (individual quanta of light). It includes the study of the particle-like properties of photons and their interaction ...

and

cavity quantum electrodynamics Cavity Quantum Electrodynamics (cavity QED) is the study of the interaction between light confined in a reflective cavity and atoms or other particles, under conditions where the quantum nature of photons is significant. It could in principle be ...

. Together with his theory group, he focuses on cavity cooling, self-organization,

quantum thermodynamics Quantum thermodynamics is the study of the relations between two independent physical theories: thermodynamics and quantum mechanics. The two independent theories address the physical phenomena of light and matter. In 1905, Albert Einstein argued ...

, light forces, superradiant lasing and

quantum metrology Quantum metrology is the study of making high-resolution and highly sensitive measurements of physical parameters using quantum theory to describe the physical systems, particularly exploiting quantum entanglement and quantum Squeezed coherent s ...

. His significant contributions in those fields have been honoured with prestigious awards and prizes, as the

Ludwig Boltzmann Prize The Ludwig Boltzmann Prize is awarded by the Austrian Physical Society and honors outstanding achievements in theoretical physics. It is named after the famous Austrian physicist Ludwig Boltzmann. The prize was established at the annual meeting o ...

(1993) of the

Austrian Physical Society The Austrian Physical Society () is the national physical society of Austria. History Until 1938, Austrian physicists were part of the German Physical Society. On 13 December 1950, it was decided to found a separate society for Austria and Fritz ...

and the Erwin Schrödinger Prize (2019) of the

Austrian Academy of Sciences The Austrian Academy of Sciences (; ÖAW) is a legal entity under the special protection of the Republic of Austria. According to the statutes of the Academy its mission is to promote the sciences and humanities in every respect and in every fi ...

Life and career

Ritsch grew up in

Stubaital The Stubai Valley or Stubaital () is an alps, alpine valley in Tyrol (state), Tyrol, Austria. It is the central valley of the Stubai Alps. The river Ruetz (river), Ruetz flows through the valley. This 35-km long valley runs in northeastern dire ...

in the neighbourhood of

. He graduated in 1980 from Akademischen Gymnasium in Innsbruck and studied physics at the

, where he finished his diploma study in 1985 with a thesis about synchrotron radiation. He began his doctoral studies under

Peter Zoller Peter Zoller (born 16 September 1952) is a theoretical physicist from Austria. He is professor at the University of Innsbruck and works on quantum optics and quantum information and is best known for his pioneering research on quantum computing ...

, which he finished in 1989 with the dissertation "Atomic Dynamics in Classical Stochastic and Quantum Light Fields". Afterwards he worked as a postdoc in Innsbruck, Konstanz, Milan, Boulder and Munich. In 1993 he was habilitated at the

(venia docendi in theoretical physics). In 1996/97 Ritsch did research at the

University of Milan The University of Milan (; ), officially abbreviated as UNIMI, or colloquially referred to as La Statale ("the State niversity), is a public university, public research university in Milan, Italy. It is one of the largest universities in Eu ...

as part of a Marie Skłodowska-Curie project. Beginning in 1998, he was associate professor, and since 2011 Helmut Ritsch is professor at the Institute for Theoretical Physics at the

. He was the head of the institute from 2009 until 2013 and from 2017 until 2021. Helmut Ritsch is married to the physicist

Monika Ritsch-Marte Monika Ritsch-Marte (born 26 September 1961 in Höchst) is an Austrian physicist in the fields of biomedical optics, theoretical quantum optics and non-linear optics. She is a professor at the Medical University of Innsbruck and director of t ...

, they have two daughters.

Research

Cavity QED

Helmut Ritsch has made significant contributions to the field of cavity quantum electrodynamics (QED), in particular to many-body cavity QED. Along his colleagues, he has developed the notion of self-organization of atoms interacting strongly with quantized radiation fields of high-Q cavities, as a manifestation of the Dicke superradiant

phase transition In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic Sta ...

. This phenomenon has been observed in many experiments, ranging from Bose-Einstein condensates to non-interacting and strongly interacting Fermi gases. The atomic self-organization in cavities is currently an active field of research, with the prospect to address some of the most challenging, open questions in nonequilibrium many-body physics in a controlled way.

Monte Carlo wave function (MCWF) method

Monte Carlo wave function method, also known as quantum jump method, is a computational tool used in dissipative systems to approximate the density matrix of a quantum system. The method was developed in 1992 independently by Dum, Zoller and Ritsch and Dalibard, Castin and Mølmer.

QuantumOptics.jl

QuantumOptics.jl is a numerical framework written in the

Julia Julia may refer to: People *Julia (given name), including a list of people with the name *Julia (surname), including a list of people with the name *Julia gens, a patrician family of Ancient Rome *Julia (clairvoyant) (fl. 1689), lady's maid of Qu ...

that facilitates simulations of various kinds of

open quantum system In physics, an open quantum system is a quantum-mechanical system that interacts with an external quantum system, which is known as the ''environment'' or a ''bath''. In general, these interactions significantly change the dynamics of the system a ...

s. It is inspired by the Quantum Optics Toolbox for MATLAB and the Python framework QuTiP. QuantumOptics.jl is being developed in Helmut Ritsch's CQED group at the Institute for Theoretical Physics of the

since 2017, with the 1.0 version being released in July 2021. QuantumOptics.jl remains

open-source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

and is hosted on

GitHub GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug trackin ...

. There are several Add-Ons related to and/or dependent on QuantumOptics.jl. For example, QuantumCumulants.jl is a package for the symbolic derivation of mean-field equations for quantum mechanical operators in Julia.

Dipole-Dipole interactions

A significant part of his research also involves the investigation of collective effects of atoms with light-induced interactions, including the emergence of superadiance and subradiance in long-range interacting quantum emitters with dipole-dipole interactions.

Honours and awards

* 2019 Erwin Schrödinger Prize of the

for his outstanding research achievements in the field of

, in particular for his fundamental contributions to the theoretical understanding of light-matter interaction and cavity quantum electrodynamics (CQED). * 2019 JILA visiting fellow award * 2008 Scottish Universities Physics Alliance (SUPA) Distinguished Visitor Award, Glasgow. * 2004 Dr. Otto Seibert Wissenschafts-Förderungs-Preis. * 1993

of the

(jointly with M. Ritsch-Marte). * 1992 Research award of the city of Innsbruck.

External links

Helmut Ritsch
Institut für Theoretische Physik, Universität Innsbruck.

group webpage.
Helmut Ritsch
publications indexed by Google Scholar.

References

{{DEFAULTSORT:Ritsch, Helmut 1962 births Living people People from Innsbruck Quantum physicists Austrian physicists Academic staff of the University of Innsbruck