Research

Physical Sciences

Title :

Studies on emergent excitations in quantum spin systems using Raman scattering

Area of research :

Physical Sciences

Principal Investigator :

Dr. Anushree Roy, Indian Institute Of Technology (IIT) Kharagpur, West Bengal

Timeline Start Year :

2022

Timeline End Year :

2025

Contact info :

Equipments :

Details

Executive Summary :

Quantum spin liquid systems have gained significant interest in recent decades due to their exotic magnetic phase, where quantum fluctuations suppress conventional magnetic ordering. The experimental identification of this magnetic phase is primarily based on macroscopic observables such as specific heat and magnetic susceptibility. However, neutron and muon scattering measurements reveal clear signatures of the quantum spin liquid phase in these compounds. Recent predictions suggest that Raman response of some ruthenate spin-liquid systems carry unique signatures for Kitaev spin liquid with Majorana fermionic excitation with Dirac-like dispersion. The superconducting mechanism in iron-based superconductors is still not well understood, with both spin fluctuations and nematic fluctuations playing a critical role. The interplay between lattice, charge, and spin degrees of freedom determines the onset of magnetism, nematicity, and superconductivity. The proposed study aims to focus on P doped BaFe2As2 compounds and other electron and hole doped 122 and 112 systems to explore the fingerprints of quantum criticality in them. Studies on phonon dynamics reveal the interplay between charge, spin, and orbital degrees of freedom of skyrmionic lattice phase. High pressure and low-temperature Raman measurements on Cu2OSeO3 probed the skyrmionic pocket in the phase diagram via structural modulation of the cubic symmetry of the system. The project proposes to explore open questions related to the correlation between spin-spin interactions and underlying lattice related to the skyrmionic phase in bi- and trilayer manganites (LaxSr1-xMnO3) perovskites and splitting of the skyrmion phase in Zn doped Cu2OSeO3.

Co-PI:

Dr. Sitikantha Dhurjati Das, Indian Institute Of Technology (IIT) Kharagpur, West Bengal-721302

Total Budget (INR):

72,05,000

Organizations involved