Bengaluru: Researchers from Raman Research Institute (RRI) and Indian Institute of Science (IISc) Bangalore, have found that phase change in certain particles like electron, proton, neutron, neutrino takes place not only in the presence of changing magnetic field but also in the presence of a gravitational field.
According to researchers, this finding brings a major change in understanding of quantum phenomena related to geometric effects governed by a gravitational field and also sheds light on the existence of primordial black holes.
A quantum particle in a varying magnetic field acquires an additional phase during its evolution known as the "Pancharatnam-Berry phase."
A related geometric effect was explored by Aharonov and Bohm due to related magnetic potential. As both magnetic and gravitational fields are geometric in nature, it is expected that similar geometric effects would appear in either of them, though for the gravitational field, it was unnoticed.
Indian researchers spotted this geometric effect of the gravitational field for the first time. They uncovered this by employing the basic quantum mechanical techniques in the relativistic regime in the background gravitational field.
The research by Tanuman Ghosh from RRI and Banibrata Mukhopadhyay from IISc published in International Journal of Modern Physics D suggested similarities between the effects arising due to gravitational and magnetic fields.
The sites of black holes of mass around 1,015 gm and slightly more would be potentially the best candidates to detect the geometric effects in the gravitational background. According to the authors, observations of specific small interference patterns by the Fermi Gamma-Ray Space Telescope can shed light on the existence of primordial black holes.
The research which extends the notion of the Aharonov-Bohm effect and the Pancharatnam-Berry phase beyond the magnetic field to the gravitational field will include new textbook material related to the semi-classical effects of electrons in gravitational fields for undergraduate and postgraduate students.
