Quantum many body systems show varieties of exotic phases at low temperatures. There the electron-phonon interactions, spin-charge separation/coupling, spin-spin interactions, spin-orbit couplings etc cause many rich phenomena like superconductivity, superfluidity or different density wave orders to appear in the condensed matter systems. Therefore quantum phase transitions or low temperature phase transitions are very active field of study in this regard. Other than analytics, tools like Quantum Monte Carlo helps big way in these fields. Few works done along these lines are as follows:

• Magnon dispersions and single hole motion in 2D frustrated antiferromagnets with four-sublattice structures, JMMM 393, 357 (2015), SK.

• Checkerboard supersolidity in 2D Bose-Holstein model, Ann. Phys. 375, 322 (2016), SK, S. Yarlagadda.

• Magnons in a two dimensional transverse field XXZ model, Phys.Rev.B96, 045126 (2017), SK, K.Wierschem, P.Sengupta.

• Mixed-order transition and tricritical point associated with checkerboard supersolidity in a two dimensional t2 − V model, Phys.Rev.B101, 0351247(2020), A.Ghosh, SK, S.Yarlagadda.

Quantum many body systems driven out of equilibrium has become a popular research topic for quite some time now. Few works done on this subject are given below:

• Tuning towards dynamic freezing using a two-rate protocol, Phys.Rev.B94, 075130 (2016), SK, B.Mukherjee, K.Sengupta.

• Two-rate periodic protocol for driving through many cycles, Phys.Rev.B95, 085141 (2017), SK.

• Andreev tunneling and Josephson current in light irradiated graphene, Cur.App.Phys.18, 1087 (2018), D.Sinha, SK.

Since its discovery in 1986, high temperature superconductors with its all variants including cuprate superconductors, Pnictide superconductors etc. has continued to remain hot in the condensed matter community. Few works done on the 2D theoretical models of cuprates are the following:

• Finite-temperature spectral function of a hole in a quantum antiferromagnet and the role of phonons, Phys.Rev.B78, 064508 (2008), SK, E.Manousakis.

• Hole spectral functions in lightly doped quantum antiferromagnets, Phys.Rev.B84, 205107 (2011), SK, E.Manousakis.

Study of topological phases in condensed matter gained huge momentum after the work of Kosterlitz-Thouless and D. Haldane and their subsequent winning of Nobel prize in 2016 for the same. Following are the few works done on that direction:

• Photo-induced Entanglement in a Magnonic Floquet Topological Insulator, Phys.Rev.B98, 245119 (2018), SK, B.Basu.

• Weyl Semimetals: Down the Discovery of Topological Phases, Asian Jour. Res. Rev. Phys. 4(1): 34 (2021), SK, A.Jayannavar.

• Quantum Oscillation and Landau-Zener transition in untilted Nodal line semimetals under a time-periodic magnetic field, J.Phys.Cond-Mat.33, 225601 (2021).