Festive Colloquium on the Occasion of Prof. Alexander Lichtenstein’s 70th Birthday

Friday 16 May 2025, 14:00 → 18:00 Europe/Berlin

Desy Hamburg (Auditorium CSSB (bldg. 15))

We are delighted to announce the festive colloquium in honor of Prof. Alexander Lichtenstein’s 70th birthday, celebrating his contributions to condensed matter theory, the theory of magnetism and electronic correlations. 

 

Prof. Lichtenstein has shaped the field of condensed matter physics through his pioneering works on correlated electron systems, dynamical mean-field theory, and advanced computational methods for real materials.

 

The colloquium will feature talks by distinguished speakers and a celebration of his scientific legacy.

 

Confirmed speaker:

 

Silke Biermann (Ecole Polytechnique)

Guy Cohen (Tel Aviv U) 

Olga Smirnova (Max Born Inst, Berlin)

Dieter Vollhardt (U Augsburg) 

 

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Remote Connection:

To allow also to follow the program from remote, the Colloquium will be accessible via a Zoom link to the outside (also for non-registered participants). Please be aware that the meeting will be recorded.

Zoom connection

Meeting ID: 659 9671 4069
Passcode: 324945

https://desy.zoom.us/j/65996714069?pwd=IpWILz9HmJiotpuLVLaeFUHcHRobrb.1

 

 

Video recordings

The video recordings can be found either attached to the agenda entries or for all the talks here: tba

1 About local and non-local correlations - A brief history of the electronic structure problem in correlated electron materials

Photon Science Colloquium

Speaker: Silke Biermann (Ecole Polytechnique)

2 Quantum Impurity Solvers: Recent Advances

Quantum impurity problems first appeared in the treatment of magnetic atoms embedded in metals, and now act as auxiliary objects within the dynamical mean field theory of correlated materials. Among Prof. Lichtenstein's many notable contributions to our current understanding of the physics of materials are his seminal work in developing Monte Carlo techniques for simulating impurity models. Yet, in many regimes and for many observables, simulations of this type remain either infeasible or extremely expensive. Here, I will discuss prospects for addressing this challenge by combining Inchworm Monte Carlo techniques with some mathematical technologies that have recently drawn attention in physics, such as tensor train cross-interpolation and pole representations.

Speaker: Guy Cohen (Tel Aviv U)

15:30 Coffee break

3 Enantio-sensitive spin-orientation locking and spin vortices induced by geometric fields in chiral molecules

Speaker: Olga Smirnova (Max Born Inst, Berlin)

4 What does it tell us when curves cross?

In physics and chemistry it is often observed that the curves of a physical quantity f(x,p) cross at one or more points, when plotted as a function of x for different values of the parameter p. Sometimes these crossing points are confined to a remarkably narrow region, or are even located at a single point, called "isosbestic point". For example, crossing points are found in the curves of the heat capacity C(T,X) of many correlated materials, with X as the pressure or the magnetic field, and of the Hubbard model, with X as the interaction U, but also in the Raman response chi''(omega,T) and many other quantities. I will explain that crossing points provide valuable information about the system in which they occur.

Speaker: Dieter Vollhardt (U Augsburg)