Superconductivity at 52 K in hole-doped C60

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• Superconductivity in electron-doped C60 fullerene was discovered a decade ago.
• Electron transfer to C60 molecules from dopants induces metallic states and superconductivity.
• Hole-doped C60 was theoretically predicted to exhibit higher superconducting transition temperatures (Tc) due to a higher density of states in the valence band.

Purpose of the Study:

• To investigate superconductivity in hole-doped C60.
• To explore the possibility of achieving higher Tc values in hole-doped C60 compared to electron-doped C60.
• To demonstrate the effectiveness of gate-induced doping for creating hole carriers in C60.

Main Methods:

• Utilized a field-effect transistor configuration for gate-induced doping.
• Introduced significant densities of holes into C60 fullerene.
• Measured the superconducting transition temperature (Tc) as a function of hole density.

Main Results:

• Observed superconductivity in hole-doped C60 over an extended range of hole densities.
• The superconducting transition temperature (Tc) varied smoothly, reaching a maximum of 52 K.
• Demonstrated the feasibility of achieving superconductivity via hole doping in C60.

Conclusions:

• Gate-induced doping is an effective method for achieving superconductivity in hole-doped C60.
• The observed Tc of 52 K in hole-doped C60 is promising.
• Extrapolation suggests that Tc values exceeding 100 K may be attainable in expanded hole-doped C60 lattices.