
Calendar of Physics Talks Vienna
Problems and prospects of the IIB matrix model 
Speaker:  Hikaru Kawai (Kyoto University) 
Abstract:  The IIB matrix model is one of the promising candidates of the constructive definition of string theory.
In this talk, we start with explaining the basic idea and the definition of the model.
We then discuss the problems and the prospects of the model such as
1) ambiguities in the definition,
2) what the matrices stand for,
3) how the spacetime emerges,
4) origin of the diffeomorphism invariance,
5) relation to the multiverse and the naturalness. 
Date:  Mon, 09.07.2018 
Time:  09:10 
Duration:  50 min 
Location:  Erwin Schrödinger Institute, Boltzmann Lecture Hall, Boltzmanngasse 9, 2nd floor, 1090 Wien 
Contact:  www.esi.ac.at 
Quantum Sensing of Weak RadioFrequency Signals by Pulsed Mollow Absorption Spectroscopy 
Speaker:  Friedemann Reinhard (Walter Schottky Institut Technische Universität München ) 
Abstract:  Solid state qubits, such as the NitrogenVacancy (NV) center in diamond, have become powerful sensors for nanoscale magnetic and electric fields, owing to their atomically small size. A major key for their success have been dynamical decoupling protocols, which boost sensitivity to tiny AC signals such as the magnetic field of nuclear spins from a single protein [1]. Currently, those methods are bound to signal frequencies below few MHz.
I will present a novel dynamical decoupling protocol [2,3] to detect weak fields close to the NV transition frequency (~3 GHz). Our scheme is a pulsed implementation of Mollow triplet spectroscopy [4], where pulsing improves sensitivity to the T2limit, the level achieved by lowfrequency protocols. As a result, we demonstrate slow Rabi oscillations with a period up to 100µs, driven by a weak signal field.
Possible applications include radioastronomy, quantum communication with single microwave photons, and the study of spinphonon coupling.

Date:  Tue, 10.07.2018 
Time:  15:00 
Location:  Atominstitut, Seminarraum, Stadionallee 2, Wien 2 
Contact:  Johannes Majer 
