We report on an observation of a fractional quantum Hall effect in an ultra-high quality two-dimensional hole gas hosted in a strained Ge quantum well. The Hall resistance reveals precisely quantized plateaus and vanishing longitudinal resistance at filling factors ν=2/3,4/3 and 5/3. From the temperature dependence around ν=3/2 we obtain the composite fermion mass of m⋆≈0.4me, where me is the mass of a free electron. Owing to large Zeeman energy, all observed states are spin-polarized and can be described in terms of spinless composite fermions.
@article{arxiv.1511.05164,
title = {Spinless composite fermions in an ultra-high quality strained Ge quantum well},
author = {Q. Shi and M. A. Zudov and C. Morrison and M. Myronov},
journal= {arXiv preprint arXiv:1511.05164},
year = {2015}
}