The electric drift-current bias was recently introduced as a new paradigm to break the Lorentz reciprocity in graphene. Here, we study the impact of the nonreciprocal response in the energy extracted from a beam of swift charges traveling in the vicinity of a graphene sheet with drifting electrons. It is demonstrated that the drift bias leads to an asymmetric electron-energy-loss spectrum that depends on the sign of the charge velocity. It is found that when the drift and electron beam velocities have comparable values but opposite signs, the energy loss is boosted resulting in a noncontact friction-type effect. In contrast, when the drift and electron beam velocities have the same sign, the energy loss is negligible. Furthermore, it is shown that different theoretical models of the drift-biased graphene conductivity yield distinct peaks for the energy-loss spectrum, and thereby electron beam spectroscopy can be used to test the validity of the different theories.

最近引入了电漂移电流偏置作为打破石墨烯洛伦兹互易性的新范例。在这里，我们研究了不可逆响应对从带有漂移电子的石墨烯片附近行进的快速电荷束中提取的能量的影响。已经证明，漂移偏置导致不对称的电子能量损失谱，该谱依赖于电荷速度的符号。发现当漂移和电子束速度具有可比较的值但符号相反时，能量损失增加，导致非接触摩擦型效应。相反，当漂移和电子束速度具有相同的符号时，能量损失可以忽略不计。此外，