Methods for quantum interference in atomic ensemble

An experimental method for obtaining quantum interference signal in atomic ensemble using a bi-chromatic field is discussed. Here, the quantum interference signal is obtained by scanning the magnetic field rather than conventional method of changing the frequency separation between the light fields. We could simultaneously observe resonances due to population redistribution and quantum superposition between non-degenerate states, which otherwise involves fundamentally different approaches. The method is implemented to Rubidium atoms in buffer gas filled as well as anti-relaxation coated atomic cells. Apart from phenomenological interest, the modified experimental procedure is found to be convenient for in-situ calibration of three axis magnetic coils. The investigation will be useful for high as well as low vector magnetic field sensing.