CNRS, Laboratoire de Photonique et de Nanostructures (LPN)-Phynano team, route de Nozay, 91460 Marcoussis, France.
Phys Rev Lett. 2010 Jul 30;105(5):056803. doi: 10.1103/PhysRevLett.105.056803. Epub 2010 Jul 27.
We investigate the energy exchanges along an electronic quantum channel realized in the integer quantum Hall regime at a filling factor of νL=2. One of the two edge channels is driven out of equilibrium and the resulting electronic energy distribution is measured in the outer channel, after several propagation lengths 0.8 μm≤L≤30 μm. Whereas there are no discernible energy transfers toward thermalized states, we find efficient energy redistribution between the two channels without particle exchanges. At long distances L≥10 μm, the measured energy distribution is a hot Fermi function whose temperature is lower than expected for two interacting channels, which suggests the contribution of extra degrees of freedom. The observed short energy relaxation length challenges the usual description of quantum Hall excitations as quasiparticles localized in one edge channel.
我们研究了在填充因子 νL=2 的整数量子霍尔效应中实现的电子量子通道中的能量交换。在经过几个传播长度 0.8 μm≤L≤30 μm 之后，两个边缘通道中的一个被驱动到非平衡状态，在外通道中测量得到的电子能量分布。虽然没有明显的能量向热化态转移，但我们发现两个通道之间没有粒子交换的有效能量再分配。在较长的距离 L≥10 μm 时，测量到的能量分布是一个热费米函数，其温度低于两个相互作用通道的预期温度，这表明存在额外自由度的贡献。观察到的短能量弛豫长度挑战了通常将量子霍尔激发描述为局域在一个边缘通道中的准粒子的描述。
