Computational study of magnetic, magnetoelectric and electronic properties of some quantum many-body systems

Abstract

Understanding the physics of interacting quantum many-body systems has gained immense attention in recent years as this governs the behavior of a huge variety of materials, such as, quantum magnetic materials, organic conductors[1] and charge transfer systems[2], multiferroics[3] and magnetoelectrics[4], conventional as well as high-Tc superconductors[5], superfluids[6], Kondo lattices[7], Quantum Hall systems[8] and many more. Such strongly correlated materials have potential applications in a range of phenomena, from electronic, energy and memory devices to spin and quantum computing. Systems in which electrons can wander almost freely, or, in other words, have a large kinetic energy with respect to the Coulomb interactions between them, can be dealt with the formalism of single particle quantum mechanics. However, interactions cannot always be neglected. For instance, in a class of f-electron systems, called heavy fermion systems,[9,10] in which the effective mass of the electrons are higher than their rest mass by several orders of magnitude. Thus, they are no longer freely moving individual electrons as electronic correlations become prominent. Still, many such interacting systems can be explained in the limits of Fermi Liquid Theory [11,12], in which the collective behaviour of such heavy electrons resemble that of non-interacting fermions with renormalized heavier masses.