Design,fabrication, and physical property manipulation of quantum aterials
Haizhong Guo
School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China

EXTENDED ABSTRACT: Perovskite structure materials are ideal systems and platforms for studying spin,orbit, charge, phonons and other quantum states and their macroscopic quantum properties (Figure 1). Thereare many degrees of freedom in perovskite structure materials such as spin, o rbit, charge, and phonons. Thereis a strong correlation and coupling effect between these degrees of freedom, which leads to many novelmacroscopic quantum phenomena , s uch as high temperature superconductivity, colossal magnetoresi stance,multiferroicity, and quantum phase transition and quantum critical phenomena. In addition, there is a strongmutual coupling and competition between these degrees of freedom, which makes the system form a series oflow energy excited states with similar energies or even c ompeting ground states, which will produce somenovel physical properties and quantum state manipulated under the external fields . The electronic structure of the material can be controlled by the strains . We use strains to control the bandgap in the SrCoO 2.5 film. Excited by an ultrafast laser, the c axis lattice constant expansion of the SrCoO 2.5film can reach 1.12%, which is the largest lattice expansion among oxides, which is called giant lat ticedistortion. High pressure is another effective method of external stress control. We prepared a lead free doubleperovskite (NH 4 2 SeBr 6 material. Under the action of pressure, it changed from a cubic phase to a newstructure at 11.2 GPa and caused the decrease of the optical band gap [ The electric field is used to controlthe SrTiO 3 /LaAlO 3 two dimensional electron gas to produce a r esistance effect .We also used stress to control LaCoO 3 and SrFeO 3 films to produce novelphysical properties [2]. In addition, we have made several breakthroughs in thepreparation, characterization, regulation and catalytic application of nano metalmaterials

REFERENCES [1]L. R. Wang, et al. Adv . 7 , 2020) 1902900
[2]S. Li, et al., Adv. Mater. 33 , ( 2001324.