Strange metal behaviour and spin fluctuations in overdoped La2-xSrxCuO4

Above their transition temperature Tc, cuprate superconductors are metals. However, the conduction electrons show very anomalous behavior compared to other metals. E.g. the resistivity is proportion to temperature (T). We believe that this "strange" behavior is connected to spin fluctuations with energies comparable to T. These spin fluctuations may scatter the conduction electrons and change (scale) in a special way with T and be connected to strange T-dependence of the resistivity. We have recently identified very low-energy (~4 meV) overdamped spin fluctuations in normal state of La2-xSrxCuO4 (x=0.22) for T close to Tc. Here we propose to measure how these excitations change with T We will compare our results to theories of magnetic quantum criticality. The results will shed light on the nature of electrons which carry charge in the cuprates.