Competition between spin ordering and superconductivity near the pseudogap boundary in La2-xSrxCuO4: insights from NMR
arxiv(2022)
摘要
When superconductivity is suppressed by high magnetic fields in La2-xSrxCuO4,
striped antiferromagnetic (AFM) order becomes the magnetic ground state of the
entire pseudogap regime, up to its end at the doping p* [M. Frachet, I.
Vinograd et al., Nat. Phys. 16, 1064 (2020)]. Glass-like freezing of this state
is detected in 139La NMR measurements of the spin-lattice relaxation rate 1/T1.
Here, we present a quantitative analysis of 1/T1 data in the hole-doping range
p=x=0.12-0.171, based on the Bloembergen-Purcell-Pound (BPP) theory, modified
to include statistical distribution of parameters arising from strong spatial
inhomogeneity. We observe spin fluctuations to slow down at temperatures T near
the onset of static charge order and, overall, the effect of the field B may be
seen as equivalent to strengthening stripe order by approaching p=0.12 doping.
In details however, our analysis reveals significant departure from usual
field-induced magnetic transitions. The continuous growth of the amplitude of
the fluctuating moment with increasing B suggests a nearly-critical state in
the B->0 limit, with very weak quasi-static moments possibly confined in small
areas like vortex cores. Further, the nucleation of spin order in the vortex
cores is shown to account quantitatively for both the value and the p
dependence of a field scale characterizing bulk spin freezing. The correlation
time of the fluctuating moment appears to depend exponentially on B/T (over the
investigated range). This explains the timescale dependence of various
experimental manifestations, including why, for transport measurements, the AFM
moments may be considered static over a considerable range of B and T. These
results make the high-field magnetic ground state up to p* an integral part of
the discussion on putative quantum criticality.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要