Hot Topics - Karl van Bibber (Berkeley) - 'Ultrasensitive Searches for the Axion'



11 AM - 1 PM


Leiden University, Snellius Building, room 312


Hot Topics in Quantum Nanoscience

Course Content: Speakers from all over the world will be asked to present pedagogical introductions to their field with an emphasis on basic concepts. Besides such an introductory lecture open for everybody, the participants of this course will have an additional discussion with the speaker discussing a recent paper and the holy grails of the field.

Exemplary topics are topological insulators, mesoscopic quantum gravity, string theory for condensed matter, measurement-based quantum computing, quantum-limited sensors, Majorana Fermions, fast-light with single photons, etc., etc.

Audience: The tutorial, as a one hour lecture, is open to everybody. A second hour will be reserved as a discussion hour for the registered class of PhD students and postdocs with the lecturer.

Preparation: PhD students who have registered for the hot topics course need to prepare for the session by reading the articles mentioned in the below.

Date & Speaker:

Tuesday 25 March, professor Karl van Bibber (University of California, Berkeley, USA)

Topic: "Ultrasensitive Searches for the Axion"


"After three decades, the axion, a hypothetical elementary particle, still represents the best solution to the Strong-CP problem, i.e. why the neutron has a vanishingly small electric dipole moment.   Should the axion exist, it would be extremely light, in the range between a micro-eV and milli-eV, and possess extraordinarily feeble couplings to matter and radiation, far beyond the reach of conventional particle physics experiments.  Very light axions would also have been produced abundantly during the Big Bang, and thus the axion represents a well-motivated dark matter candidate.  As recognized by Pierre Sikivie in 1983, the coherent mixing of axions and photons in a strong magnetic field of large spatial extent provides the strategy for elegant and ultrasensitive experiments that may finally render the axion observable.  This talk will primarily review the microwave cavity search for halo dark matter axions (AMDX & ADMX-HF); but also briefly discuss the search for solar axions, and purely laboratory experiments, such as photon regeneration (“shining light through the wall”). The searched-for signals are nevertheless still extremely small, and thus axion searches have proven to be a driver for technology innovation, such as sub-quantum-limited Josephson Parametric Amplifiers and hybrid superconducting microwave cavities for the dark matter axion experiment."

Required reading: see the downloadable files in the below.

Host:         Prof. dr. Ana Achúcarro
Leiden University, Snellius building, room 312.
11:00 - 12:00 hot topics lecture, 12:00 - 13:00 lunch and hot topics discussion

Are you coming from Delft to Leiden? Take the train! Note that -due to the safety measures related to the NSS- traveling by car between Delft and Leiden is virtually impossible on this day. Trains and buses will run normally. For more information, check this website.