T.C.M. Group, Cavendish Laboratory, Cambridge, United Kingdom.
Phys Rev Lett. 2012 Aug 17;109(7):075302. doi: 10.1103/PhysRevLett.109.075302. Epub 2012 Aug 16.
We consider a single impurity immersed in a Fermi sea close to an interspecies p-wave Feshbach resonance. We calculate its dispersion and spectral response to a radio frequency pulse. In a magnetic field, dipolar interactions split the resonance and two novel features with respect to the s-wave case appear: a third polaron branch in the excitation spectrum, in addition to the usual attractive and repulsive ones; and an anisotropic dispersion of the impurity characterized by different effective masses perpendicular and parallel to the magnetic field. The anisotropy can be tuned as a function of the field strength and the two effective masses may have opposite signs, or become smaller than the bare mass.
我们考虑了一个处于费米海中的单个杂质，该杂质接近一个异种族 p 波的费什巴赫共振。我们计算了它的色散和对射频脉冲的光谱响应。在磁场中，偶极相互作用分裂了共振，与 s 波情况相比出现了两个新的特征：除了通常的吸引和排斥极化子分支外，激发谱中还出现了第三个极化子分支；杂质的各向异性色散，其特点是垂直于磁场和平行于磁场的有效质量不同。各向异性可以作为场强的函数进行调节，并且两个有效质量可能具有相反的符号，或者变得小于裸质量。
