ترغب بنشر مسار تعليمي؟ اضغط هنا

Superexchange coupling and spin susceptibility spectral weight in undoped monolayer cuprates

78   0   0.0 ( 0 )
 نشر من قبل Bourges
 تاريخ النشر 1997
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

A systematic inelastic neutron scattering study of the superexchange interaction in three different undoped monolayer cuprates (La_2CuO_4, Nd_2CuO_4 and Pr_2CuO_4) has been performed using conventional triple axis technique. We deduce the in-plane antiferromagnetic (AF) superexchange coupling $J$ which actually presents no simple relation versus crystallographic parameters. The absolute spectral weight of the spin susceptibility has been obtained and it is found to be smaller than expected even when quantum corrections of the AF ground state are taken into account.



قيم البحث

اقرأ أيضاً

We report a detailed study of the temperature and magnetic-field dependence of the spin susceptibility for a single crystal of La(1.875)Ba(0.125)CuO(4). From a quantitative analysis, we find that the temperature-dependent anisotropy of the suscepti bility, observed in both the paramagnetic and stripe-ordered phases, directly indicates that localized Cu moments dominate the magnetic response. A field-induced spin-flop transition provides further corroboration for the role of local moments. Contrary to previous analyses of data from polycrystalline samples, we find that a commonly-assumed isotropic and temperature-independent contribution from free carriers, if present, must be quite small. Our conclusion is strengthened by extending the quantitative analysis to include crystals of La(2-x)Ba(x)CuO(4) with x=0.095 and 0.155. On the basis of our results, we present a revised interpretation of the temperature and doping dependence of the spin susceptibility in La(2-x)(Sr,Ba)(x)CuO(4).
568 - Vivek Mishra , M. R. Norman 2015
Charge order has emerged as a generic feature of doped cuprates, leading to important questions about its origin and its relation to superconductivity. Recent experiments on two classes of hole doped cuprates indicate a novel d-wave symmetry for the order. These were motivated by earlier spin fluctuation theoretical studies based on an expansion about hot spots in the Brillouin zone that indicated such order would be competitive with d-wave superconductivity. Here, we reexamine this problem by solving strong coupling equations in the full Brillouin zone. Our results find that bond-oriented order, as seen experimentally, is strongly suppressed, indicating that the charge order must have a different origin.
We report an infrared optical study of the pnictide high-temperature superconductor BaFe$_{1.84}$Co$_{0.16}$As$_{2}$ and its parent compound BaFe$_{2}$As$_{2}$. We demonstrate that electronic correlations are moderately strong and do not change acros s the spin-density wave transition or with doping. By examining the energy scale and direction of spectral weight transfer, we argue that Hunds coupling emph{J} is the primary mechanism that gives rise to correlations.
We develop a novel self-consistent approach for studying the angle resolved photoemission spectra (ARPES) of a hole in the t-J-Holstein model giving perfect agreement with numerically exact Diagrammatic Monte Carlo data at zero temperature for all re gimes of electron-phonon coupling. Generalizing the approach to finite temperatures we find that the anomalous temperature dependence of the ARPES in undoped cuprates is explained by cooperative interplay of coupling of the hole to magnetic fluctuations and strong electron-phonon interaction.
Unconventional symmetry-breaking phenomena due to nontrivial order parameters attract increasing attention in strongly correlated electron systems. Here, we predict theoretically the occurrence of nanoscale spontaneous spin-current, called the spin l oop-current (sLC) order, as a promising origin of the pseudogap and electronic nematicity in cuprates. We reveal that the sLC is driven by the odd-parity electron-hole condensation that are mediated by transverse spin fluctuations around the pseudogap temperature $T^*$. At the same temperature, odd-parity magnon pair condensation occurs. The sLC order is hidden in that neither internal magnetic field nor charge density modulation is induced, whereas the predicted sLC with finite wavenumber naturally gives the Fermi arc structure. In addition, the fluctuations of sLC order work as attractive pairing interaction between adjacent hot spots, which enlarges the d-wave superconducting transition temperature $T_c$. The sLC state will be a key ingredient in understanding the pseudogap, electronic nematicity as well as superconductivity in cuprates and other strongly correlated metals.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا