Dynamic modulation of two dimensional electron gas at the oxide heterostructure with external stimuli

Abstract

P. W. Anderson in his noble article quoted More is different . His quote highlighted a key newlineaspect of complex systems, indicating that emergent properties arise at different levels of newlinecomplexity that cannot be easily predicted from the properties of individual components alone. newlineThe Dirac equation introduced almost a century ago, unified special relativity and quantum newlinemechanics, predicting helicity, Chern numbers, and Weyl fermions. Its impact extends beyond newlineparticle physics to low-dimensional condensed matter physics, facilitated by the fabrication of newline2D structures like graphene, enabling the realization of these theoretical constructs. newlineSemiconductor physics has evolved from theoretical to practical applications, particularly in newlinespintronics and quantum devices. Group-IV elements, such as silicon and germanium, have newlinedominated semiconductor physics due to their electrical characteristics and availability. Group newlineIII-V alloys, which combine elements like aluminium, gallium, and indium with nitrogen, newlinephosphorus, or arsenic, offer a wider range of electrical characteristics and bandgap engineering newlinepossibilities. Artificial heterostructures have been created by layering different semiconductor newlinematerials with controlled thicknesses and compositions, enabling the creation of two- newlinedimensional electron gas (2DEG). This discovery has led to the quantum Hall effect (QHE) and newlinefractional quantum Hall effect (FQHE), providing insights into electron behaviour and paving newlinethe way for new electronic devices. Transition metal oxides (TMOs) offer unique opportunities newlinefor studying physical characteristics due to their spin, lattice, and orbital degrees of freedom, as newlinewell as high electron correlations. TMOs are advantageous over semiconductors for spintronic newlineapplications due to their ability to integrate various emergent phenomena and exhibit a wide newlinerange of electronic, optical, and magnetic properties, including insulating, semiconducting, newlinemetallic, superconducting, ferroelectric, pyroelectric, piezoelectric, ferromagnetic, multiferro