Coexistence of Two Components in Magnetic Excitations of La${}_{2-x}$Sr${}_x$CuO${}_4$ ($x$ = 0.10 and 0.16)

Abstract

To elucidate the spin dynamics of La${}_{2-x}$Sr${}_x$CuO${}_4$, which couples with the charge degree of freedom, the spin excitations spanning the characteristic energy ($E_{\mathrm{cross}}$ $\sim$35-40 meV) are investigated for underdoped $x$ = 0.10 and optimally doped (OP) $x$ = 0.16 through inelastic neutron scattering measurements. Analysis based on a two-component picture of high-quality data clarified the possible coexistence of uprightly standing incommensurate (IC) excitations with gapless commensurate (C) excitations in the energy-momentum space. The IC component weakens the intensity toward $E_{\mathrm{cross}}$ with increasing energy transfer ($\hslash \omega$), whereas the C component strengthens at high-$\hslash \omega$ regions. The analysis results imply that the superposition of two components with a particular intensity balance forms an hourglass-shaped excitation in appearance. Furthermore, the temperature dependence of the intensity of each component exhibits different behaviors; the IC component disappears near the pseudo-gap temperature ($T$*) upon warming, whereas the C component is robust against temperature. These results suggest the itinerant electron spin nature and the localized magnetism of the parent La${}_2$CuO${}_4$ in IC and C excitations, respectively, similar to the spin excitations in the OP YBa${}_2$Cu${}_3$O${}_{6+\delta }$ and HgBa${}_2$CuO${}_{4+\delta }$ with higher superconducting-transition temperatures.

7 pages, 6 figure, 1 table

References in corpus (8)

• Two energy scales in the spin excitations of the high-T_c superconductor La${}_{2-x}$Sr${}_x$CuO${}_4$
• Anomalous High-Energy Spin Excitations in La2CuO4
• The Persistence of High-Frequency Spin Fluctuations in Overdoped La${}_{2-x}$Sr${}_x$CuO${}_4$ ($x$=0.22)
• Magnetic excitations in a bond-centered stripe phase: Spin waves far from the semi-classical limit
• The emergence of coherent magnetic excitations in the pseudogap phase of La2-xSrxCuO4
• Doping dependence of the magnetic excitations in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Hourglass dispersion and resonance of magnetic excitations in the superconducting state of the single-layer cuprate HgBa2CuO4+δ near optimal doping
• High-energy magnetic excitations from dynamic stripes in LBCO (x=1/8)

Cited by in corpus (6)

• Cuprate superconductors as viewed through a striped lens
• Topological Doping and Superconductivity in Cuprates: An Experimental Perspective
• One- and two-particle correlation functions in the cluster perturbation theory for cuprates
• Crossover from Fermi Arc to Full Fermi Surface
• Thermal Hall Effect and Neutral Spinons in a Doped Mott Insulator
• Spin excitations coupled with lattice and charge dynamics in La${}_{2-x}$Sr${}_x$CuO${}_4$