Possibility of an ordered state of spins and holes in single-crystalLa2−xSrx

Abstract

Zero-field ͑ZF͒ and longitudinal-field ͑LF͒ muon spin relaxation (SR) measurements have been carried out in the overdoped single crystals of La 2Ϫx Sr x Cu 1Ϫy Zn y O 4 with xϭ0.21, yϭ0 and 0.01. In the case of the Zn-substituted crystal with xϭ0.21 and yϭ0.01 in which the high-T c superconductivity is almost suppressed, the ZF-and LF-SR measurements have revealed the existence of a static ordered state of Cu spins at low temperatures below 2 K. No clear coherent precession of the muon spin has been observed down to 20 mK. Slowing down of the Cu-spin fluctuations has also been observed in the non-Zn-substituted crystal with x ϭ0.21 and yϭ0 at low temperatures below about 0.8 K in ZF, indicating that the observed magnetic anomaly is an intrinsic property at xϭ0.21. These SR results suggest a strong possibility of the existence of a spin/charge ordered state at xϭ0.21 in the overdoped region.

Correlation between superconductivity and in-plane resistivity in La2-xSrxCuO4

“…Although c also shows metallic temperature dependence in the overdoped LSCO at ambient pressure, the low temperature upturn of c at high pressures is reported by Goko et al 25) In addition, we can not overlook the effect of the apical oxygen, which will give rise to stronger perturbation on the electronic state of confined carriers in the CuO 2 planes with increasing pressure. The other is that x ¼ 0:22 is close to a critical Sr concentration reported by Watanabe et al 26) They measured the muon spin relaxation of Zn doped LSCO with x ¼ 0:21, suggesting the possible existence of a spin/charge ordered state.…”

Absence of the impurity-induced magnetic order in the electron-doped high-Tc cuprates Pr0.86LaCe0.14Cu1−y(Zn,Ni)yO4

“…This is interpreted as a result of the strong pinning effect of Zn on the dynamically fluctuating stripes of spins and holes [8,9]. Similar effects of Zn on the Cu-spin dynamics has been observed in the hole-doped Bi 2 Sr 2 Ca 1- [10,11] and YBa 2 Cu 3-2y Zn 2y O 7-δ [12] as well.…”

“…The temperature dependence of the spectra is similar to one another. No impurity-induced slowing down of the Cu-spin fluctuations is detected for moderately oxygen-reduced samples of the small and large δ, which is very different from the results of the hole-doped high-T c cuprates [6][7][8][9][10][11][12]. This may be understood in two ways.…”

“…This may be understood in two ways. First, there may be no dynamically fluctuating stripes of spins and electrons in the electron-doped system, because the dynamical stripes lead to the impurity-induced magnetic order in the hole-doped system [8,9]. Second, Pr 0.86 LaCe 0.14 CuO 4 may be situated in the overdoped regime, because Cu spins fluctuate so fast that the measured lowest temperature of 2 K is too high to detect the slowing down of the Cu-spin fluctuations in the overdoped regime of the hole-doped La 2-…”

POSSIBLE CHARGE AND/OR SPIN ORDERING IN THE Bi-2212, Y-123 AND La-214 PHASES

“…In the Zn-substituted crystal with x = 0.21, the electrical resistivity exhibits upturn at low temperatures below ~ 80 K and the temperature dependence of the thermoelectric power is also anomalous. Prom the /iSR measurements, 18,26 it has been found that the magnetic correlation is enhanced at low temperatures below 3.5 K in the 1% Zn-substituted crystal with x = 0.21, while it is enhanced below 0.8 K in the Zn-free one. Prom the JJLSR measurements of the 1% Zn-substituted crystal with x = 0.21 under LF, moreover, it has been found that the muon-spin depolarization rate exhibits a nearly squareroot LF-dependence at 3.0 K as observed in the Bi-2212 sample with p ~ 1/8 and that all of the Cu spins are frozen at 0.30 K. These results suggest that the dynam- ical stripe-order is slowly fluctuating at 3.0 K and changes to a static short-range stripe-order at 0.30 K. According to the recent experiment of the elastic neutron-scattering by Kimura et a/., 27 incommensurate peaks around (7r,7r), which are similar to those observed from the inelastic neutron-scattering experiment in the overdoped region, have been observed in the 1% Zn-substituted crystal with x = 0.21.…”