2022 New Investigator Grant
Simranjeet Singh, Ph.D.
Probing quantum spin liquid state in van der Waals-based systems via spin flux and spin dynamics
Abstract
Magnetic properties of materials arise from the collective interaction of electrons on atoms within a crystal. Electrons possess magnetic behavior through the quantum mechanical property of spin. Below a certain temperature, the electron spins in magnetic materials “freeze” to form an ordered state of matter: Either a ferromagnet (neighboring spins point in the same direction) or an antiferromagnet (neighboring spins pointing in opposite directions). But theory predicts a departure from commonly found magnetic ordered states, indicating that the magnetic ordering can be suppressed due to quantum mechanical fluctuations of the spins such that the spin-ensemble in a material would remain in a liquid-like state, even if the system is cooled to absolute zero temperature. Instead, such fluctuations lead to the emergence of macroscopic entanglement between spin states in a solid-state system and such a state is referred to as quantum spin liquid (QSL). The QSL is a new state of matter with properties researchers never encountered before. There are dramatic examples of emergent phenomena in QSL that could have an important role in theories describing high-transition-temperature superconductors and may have applications in quantum information science. This novel experimental approach, based on spin flux and spin dynamics, is to study layered QSL materials. The scientific goal of this proposal is to demonstrate the first electrical based detection of evasive QSL phase and experimental evidence of spinon, which are quasiparticles, in mesoscopic-sized candidate QSL systems. This work will probe the effect of reduced dimensionality, coupling with external electromagnetic fields, and the complete phase space diagram of massively degenerate ground spin-states in QSL phase. If successful, this approach will establish a clear experimental signature of QSL state in atomically thin layers, which is essential for utilizing QSL phenomena for topological quantum computing and quantum sensing applications.