Deciphering the mechanism of animal magnetic navigation: Geometric phase

by Prof. Ronnie Kosloff

HUJI

at Quantum optics seminar

Wed, 03 May 2023, 16:00
Sacta-Rashi Building for Physics (54), room 207

Abstract

Note that the seminar will be given in-person at the seminar room.

Abstract:
Magnetic sensing is commonly found in migratory species, and was shown to depend on ambient
blue/UV light. We hypothesize that visual opsin with a deprotonated retinal Schiff base as a
chromophore can function as a directional magnetic sensor. This photoreceptor protein is embedded
in a stack of oriented membranes aligned to the visual axis. The absorption in the blue/UV region
of the spectrum is due to the deprotonation of the Schiff base moiety. This form gives rise to n-\pi*
excited states which enables intersystem crossing with the bright \pi-\pi*
excited state. As a result magnetic sensitive triplet electronic states are formed. These triplets are the source of magnetic
sensing. A quantum phenomena based on the geometric phase accumulated by the rotation of
the molecule around the magnetic field axis operates as an interformeter. The actual double bond
isomerization of the retinal chromophore in the excited state around the magnetic axis is the source
of magnetic sensing. Magnetic directional sensitivity is then superimposed on the blue/UV visual
signal.

Created on 01-05-2023 by Folman, Ron (folman)
Updaded on 01-05-2023 by Folman, Ron (folman)