Research Projects

Throughout history, studies of various constituents of matter, via theoretical and experimental studies on atoms and their spectra, have always been crucial in our quest to understand fundamental physics. Atoms and molecules continue to be indispensable in exploring physics beyond the Standard Model (BSM) of elementary particles, as they are natural laboratories to understand such effects. A traditional view of atomic and molecular structure considers only electromagnetic interactions between their constituent electrons and nuclei. To explore new physics, additional interactions need to be included to probe low-energy signatures of the weak force, including the electron electric dipole moment (EDM) and parity non-conservation (PNC). Such non-accelerator methods, which look for yielding signatures of subtle effects arising due to fundamental interactions by combining precise table-top observations with accurate theoretical calculations, are gaining ground steadily in the past few decades. In the past, we have investigated PNC and EDMs in both atomic and molecular systems and reported upper limits to the neutron EDM, proton EDM, chromo-EDMs of the combined up- and down-quarks, as well as to the chromodynamics parameter from EDM studies of closed-shell atoms. Similarly, we have stringently constrained low-energy effective electron-quark couplings, isospin conserving oblique parameter, and mass of an extra $Z_x$ boson by carrying out PNC studies in the Cs atom. These interdisciplinary studies are at the forefront of both fundamental and applied atomic physics, with close collaboration between experimental and theoretical research. We would like to develop two-valence Fock-space and equation-of-motion coupled-cluster methods in the relativistic framework to carry out PNC and EDM studies in both atomic and molecular systems. Among the available methods, the relativistic normal coupled-cluster (RNCC) method is more robust to study the aforementioned atomic properties, but currently only applicable to closed-shell systems; we plan to extend it to open-shell atoms. The other interesting new phenomena that we are keenly interested to probe is the non-linear effects to the isotope shifts in the atoms due to exchange of a possible vector boson between electrons and atomic nucleus. This problem has drawn a lot of attention in the atomic physics community recently. To this end, we plan to extend our relativistic methods to evaluate the otherwise neglected second-order effects to isotope shift. Today it is the age of quantum computing, so quantum simulation of many-body systems is widely recognized as a very important application of quantum computing. We will use the relativistic variational quantum eigensolver algorithm to calculate properties of heavy and superheavy single valence atomic and molecular systems, including EDMs and PNC, utilizing the promised speedup offered in quantum mechanical calculations on quantum computers.