Generation of the low-density liquid phase of carbon by non-thermal melting of fullerite

By using femtosecond laser excitation, non-thermal melting of fullerite has been experimentally achieved. Because the ultrafast, non-thermal transition occurs approximately at constant volume, the density of the resulting liquid is 25% lower than for non-thermally molten graphite. Tight-binding molecular-dynamics simulations indicate the formation of the low-density liquid phase, composed by sp -bonded chains at 7900 K and 7 GPa. The extracted dc resistivity of the liquid (2 mΩ cm) is in agreement with theoretical predictions (2.5 mΩ cm) for the equilibrium low-density phase.