Study of Behaviour and Nature of Doping Holes in Under Doped and Overdoped Regimes Cuprate Perovskites

After more than 15 years of intens e res earch s ince the dis covery of high-te mperature s uperconductivity [1], many interes ting phys ical phenomena unique to the cuprate s uperconductors are better unders tood, and various applications have been realized. However, the underly ing mechanis m for high -te mperature s uperconductivity rema ins elus ive, la rgely due to the complication of nu merous competing orders in the ground s tate of the cuprates . We revie w s ome of the mos t important phys ics is sues and recent expe rimental develop ments ass ociated with thes e s trongly correlate d electronic s ys tems , and dis cus s current understanding and poss ible future res earch direct ion.