PGI Kolloquium - Extraordinary Talk: Prof. Dr. Stephan Appelt, Forschungszentrum Jülich (ZEA-2) and RWTH Aachen (ITMC), Germany

Hybrid Event

Please note: A limited number of seats in the PGI Lecture Hall are available by registration only. You may furthermore join by video conference. Detailed information will be communicated by email, usually about a week before the lecture takes place. It is also available on request from the contact person below

The RASER, a quantum sensor for exploring order and chaos

In this colloquium I will discuss the physics of the parahydrogen pumped RASER (Radio-frequency Amplification by Stimulated Emission of Radiation) [1], which is an ideal quantum sensor for exploring self-organized phenomena between spins and photons. RASER activity can be observed if the low-frequency photons of a high Q resonator [2] interact with a negatively polarized nuclear spin ensemble.

The theory, which describes the dynamics of multimode RASER action [3,4], predicts the appearance of frequency combs, period doubling, chaos [4] and synchronization phenomena. Recent experiments using RASER active protons pumped by SABRE (Signal Amplification By Reversible Exchange) reveal all these phenomena in the presence of a magnetic field gradient. The applications range from ultra-high resolution NMR spectroscopy, to magnetic field and rotational sensors [3] and to a new form of magnetic resonance imaging [5].

[1] M. Suefke, S. Lehmkuhl, A. Liebisch, B. Bluemich, S. Appelt, Nat. Phys. 13, 568 (2017).

[2]  M. Suefke, A. Liebisch, B. Blümich, S. Appelt, Nat. Phys. 11, 767 (2015).

[3] S. Appelt, A. Kentner, S. Lehmkuhl, B. Blümich, Prog. Nucl. Magn. Reson. Spectrosc.114-115, 1 (2019).

[4] S. Appelt, S. Lehmkuhl, S. Fleischer, B. Joalland, N.W. Ariyasingha, E. Y. Chekmenev, T. Theis, J. Magn. Reson. 322, 106815 (2021).

[5] S. Lehmkuhl, S. Fleischer, L. Lohmann, M. S. Rosen, E. Y. Chekmenev, A. Adams, T. Theis,  S. Appelt, RASER MRI: Magnetic Resonance Images formed Spontaneously exploiting Cooperative Nonlinear Interaction, accepted by Science Advances (2022).

Kontakt

PD Dr Oleg Petracic

Telefon: +49 2461 61-4519
Fax: +49 2461 61-2610
E-Mail: o.petracic@fz-juelich.de