Doping induced insulator-metal transition in the platinum based MX complexes

摘要

Platinum halide linear chain MX (X = Cl, Br, I) complexes exhibit various strengths of the charge-density-wave (CDW) ground state. One way of characterizing the strength is to study the response to charge doping. On a finite length chain, we found that PtCl preserves its CDW pattern while forming a polaron array when doped; PtI is rapidly unstable against charge doping and undergoes an insulator-metal transition easily; PtBr is in between PtCl and PtI. These trends are consistent with the CDW strength, which is strong for PtCl, medium for PtBr and very weak for PtI.