Q-dependence of spin excitations in high-T(C) cuprates from spin-phonon coupling.
نویسنده
چکیده
An understanding of spin excitations in cuprates is essential since the mechanism of high-T(C) superconductivity might be linked to spin fluctuations. Band calculations for 'one-dimensional' unit cells of La(2)CuO(4) show larger coupling (spin-phonon coupling, SPC) between anti-ferromagnetic spin waves and O-phonons than for Cu- or La-phonons. When this result is applied to a two-dimensional, free-electron like band, it leads to an 'hourglass' shape of the spin excitation spectrum, as in recent experiments. Isotope shifts and doping dependences of the excitations are discussed.
منابع مشابه
Heat Transport in Spin Chains with Weak Spin-Phonon Coupling.
The heat transport in a system of S=1/2 large-J Heisenberg spin chains, describing closely Sr(2)CuO(3) and SrCuO(2) cuprates, is studied theoretically at T≪J by considering interactions of the bosonized spin excitations with optical phonons and defects. Treating rigorously the multiboson processes, we derive a microscopic spin-phonon scattering rate that adheres to an intuitive picture of phono...
متن کاملAnalysis of the elementary excitations in high-T(c) cuprates: explanation of the new energy scale observed by angle-resolved photoemission spectroscopy.
We analyze the energy and momentum dependence of the elementary excitations in high- T(c) superconductors resulting from the coupling to spin fluctuations. As a result of the energy dependence of the self-energy Sigma(k,omega), characteristic features occur in the spectral density explaining the "kink" in recent angle-resolved photoemission spectroscopy experiments. We present results for the s...
متن کاملRenormalization of the elementary excitations in hole- and electron-doped cuprates due to spin fluctuations
Extending our previous studies we present results for the doping, momentum, frequency, and temperature dependence of the kinklike change of the quasiparticle velocity resulting from the coupling to spin fluctuations. In the nodal direction a kink is found in both the normal and superconducting state while in the antinodal direction a kink occurs only below Tc due to the opening of the supercond...
متن کاملPossible isotope effect on the resonance peak formation in high-Tc cuprates
Within effective t-J Hamiltonian we analyze the influence of electronic correlations and electron-phonon interaction on the dynamical spin susceptibility in layered cuprates. We find an isotope effect on the resonance peak in the magnetic spin susceptibility Im x(q,v), seen by inelastic neutron scattering. It results from both the electron-phonon coupling and the electronic correlation effects ...
متن کاملCoupled magnon-phonon excitations in Sr2CuCl2O2 at high pressure
High-pressure optical experiments have been performed on midinfrared excitations unique to the layered cuprates, yet whose physical origin has been unresolved. Measurements of high-pressure midinfrared spectra of Sr2CuCl2o2 unambiguously identify the ;2800-cm 21 absorption as an unusual quasibound two-magnon 1 phonon excitation. We further show that the broad peak centered near ;4000 cm is a fo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of physics. Condensed matter : an Institute of Physics journal
دوره 21 14 شماره
صفحات -
تاریخ انتشار 2009