Neutrino oscillations occur due to non-zero masses and mixings and most importantly they are believed to maintain quantum coherence even over astrophysical length scales. In the present study, we explore the quantumness of three flavour neutrino osci
llations by studying the extent of violation of Leggett-Garg inequalities (LGI) if non-standard interactions are taken into account. We report an enhancement in violation of LGI with respect to the standard scenario for appropriate choice of NSI parameters.
We study the effects of non-standard interactions on the oscillation pattern of atmospheric neutrinos. We use neutrino oscillograms as our main tool to infer the role of non-standard interactions (NSI) parameters at the probability level in the energ
y range, $E in [1,20]$ GeV and zenith angle range, $cos theta in [-1,0]$. We compute the event rates for atmospheric neutrino events in presence of NSI parameters in the energy range $E in [1,10]$ GeV for two different detector configurations - a magnetized iron calorimeter and an unmagnetized liquid Argon time projection chamber which have different sensitivities to NSI parameters due to their complementary characteristics. As an application, we discuss how NSI parameter, $epsilon_{mutau}$ impacts the determination of the correct octant of $theta_{23}$.
