Brunel D, Berthou S, Parret R, Vialla F, Morfin P, Wilmart Q, Fève G, Berroir J-M, Roussignol P, Voisin C, Plaçais B
Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité, 24 rue Lhomond, 75231 Paris Cedex 05, France.
J Phys Condens Matter. 2015 Apr 29;27(16):164208. doi: 10.1088/0953-8984/27/16/164208. Epub 2015 Apr 2.
We report on electron cooling power measurements in few-layer graphene excited by Joule heating by means of a new setup combining electrical and optical probes of the electron and phonon baths temperatures. At low bias, noise thermometry allows us to retrieve the well known acoustic phonon cooling regimes below and above the Bloch-Grüneisen temperature, with additional control over the phonon bath temperature. At high electrical bias, we show the relevance of direct optical investigation of the electronic temperature by means of black-body radiation measurements. In this regime, the onset of new efficient relaxation pathways involving optical modes is observed.
我们通过一种结合了电子和声子浴温度的电学和光学探针的新装置，报告了在焦耳加热激发的少层石墨烯中的电子冷却功率测量结果。在低偏压下，噪声测温法使我们能够在布洛赫 - 格林艾森温度上下检索到众所周知的声学声子冷却机制，并额外控制声子浴温度。在高电偏压下，我们通过黑体辐射测量展示了对电子温度进行直接光学研究的相关性。在这种情况下，观察到了涉及光学模式的新的高效弛豫途径的出现。
