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 space-time 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

Quantum Sensing of Weak Radio-Frequency Signals by Pulsed Mollow Absorption Spectroscopy
Speaker:Friedemann Reinhard (Walter Schottky Institut Technische Universität München )
Abstract:Solid state qubits, such as the Nitrogen-Vacancy (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 T2-limit, the level achieved by low-frequency protocols. As a result, we demonstrate slow Rabi oscillations with a period up to 100µs, driven by a weak signal field. Possible applications include radio-astronomy, quantum communication with single microwave photons, and the study of spin-phonon coupling.
Date: Tue, 10.07.2018
Time: 15:00
Location:Atominstitut, Seminarraum, Stadionallee 2, Wien 2
Contact:Johannes Majer