Institut Néel, CNRS and Université Grenoble Alpes, BP 166, F-38042 Grenoble, France.
Phys Rev Lett. 2013 Sep 27;111(13):136803. doi: 10.1103/PhysRevLett.111.136803. Epub 2013 Sep 24.
We report on cotunneling spectroscopy magnetoconductance measurements of multihole ultraclean carbon nanotube quantum dots in the SU(4) Kondo regime with strong spin-orbit coupling. Successive shells show a gradual weakening of the Kondo effect with respect to the spin-orbital splittings, leading to an evolution from SU(4) to SU(2) symmetry with a suppressed conductance at half-shell filling. The extracted energy level spectrum, overall consistent with negligible disorder in the nanotube, shows in the half filled case large renormalizations due to Coulombian effects.
我们报告了在 SU(4) Kondo 区具有强自旋轨道耦合的多空超洁净碳纳米管量子点的隧道谱磁导率测量结果。随着自旋轨道劈裂的增加，各壳层的 Kondo 效应逐渐减弱，导致从 SU(4)对称性演变为 SU(2)对称性，在半壳层填充时电导受到抑制。提取的能级谱与纳米管中可忽略的无序总体上一致，在半填充情况下，由于库仑效应，出现了较大的重整化。
