اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدUnidirectional spin density wave state in metallic (Sr1-xLax)2IrO4
49
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Materials that exhibit both strong spin orbit coupling and electron correlation effects are predicted to host numerous new electronic states. One prominent example is the Jeff =1/2 Mott state in Sr2IrO4, where introducing carriers is predicted to manifest high temperature superconductivity analogous to the S=1/2 Mott state of La2CuO4. While bulk superconductivity currently remains elusive, anomalous quasi-particle behaviors paralleling those in the cuprates such as pseudogap formation and the formation of a d-wave gap are observed upon electron-doping Sr2IrO4. Here we establish a magnetic parallel between electron-doped Sr2IrO4 and hole-doped La2CuO4 by unveiling a spin density wave state in electron-doped Sr2IrO4. Our magnetic resonant x-ray scattering data reveal the presence of an incommensurate magnetic state reminiscent of the diagonal spin density wave state observed in the monolayer cuprate (La1-xSrx)2CuO4. This link supports the conjecture that the quenched Mott phases in electron-doped Sr2IrO4 and hole-doped La2CuO4 support common competing electronic phases.
قيم البحث
اقرأ أيضاً
We report unexpected features of the transport in the dielectric spin density wave (SDW) phase of the quasi one-dimensional compound (TMTSF)_2PF_6: the resistance exhibits a maximum and a subsequent strong drop as temperature decreases below approxim
ately 2K. The maximum in R(T) is not caused by depinning or Joule heating of the SDW. The characteristic temperature of the R(T) maximum and the scaling behavior of the resistance at different magnetic fields B evidence that the non-monotonic R(T) dependence has an origin different from the one known for the quantum Hall effect region of the phase diagram. We also found that the borderline T_0(B,P) which divides the field induced SDW region of the P-B-T phase diagram into the hysteresis and non-hysteresis domains, terminates in the N=1 sub-phase; the borderline has thus no extension to the SDW N=0 phase.
Charge density wave (CDW) order is an emergent quantum phase that is characterized by a periodic lattice distortion and charge density modulation, often present near superconducting transitions. Here we uncover a novel inverted CDW state by using a f
emtosecond laser to coherently over-drive the unique star-of-David lattice distortion in 1T-TaSe$_2$. We track the signature of this novel CDW state using time- and angle-resolved photoemission spectroscopy and time-dependent density functional theory, and validate that it is associated with a unique lattice and charge arrangement never before realized. The dynamic electronic structure further reveals its novel properties, that are characterized by an increased density of states near the Fermi level, high metallicity, and altered electron-phonon couplings. Our results demonstrate how ultrafast lasers can be used to create unique states in materials, by manipulating charge-lattice orders and couplings.
The nature of spin-density wave and its relation with superconductivity are crucial issues in the newly discovered Fe-based high temperature superconductors. Particularly it is unclear whether the superconducting phase and spin density wave (SDW) are
truly exclusive from each other as suggested by certain experiments. With angle resolved photoemission spectroscopy, we here report exchange splittings of the band structures in Sr1-xKxFe2As2 (x=0,0.1,0.2), and the non-rigid-band behaviors of the splitting. Our data on single crystalline superconducting samples unambiguously prove that SDW and superconductivity could coexist in iron-pnictides.
Starting from exact expression for the dynamical spin susceptibility in the time-dependent density functional theory a controversial issue about exchange interaction parameters and spin-wave excitation spectra of itinerant electron ferromagnets is re
considered. It is shown that the original expressions for exchange integrals based on the magnetic force theorem (J. Phys. F14 L125 (1984)) are optimal for the calculations of the magnon spectrum whereas static response function is better described by the ``renormalized magnetic force theorem by P. Bruno (Phys. Rev. Lett. 90, 087205 (2003)). This conclusion is confirmed by the {it ab initio} calculations for Fe and Ni.
Via spin-polarized scanning tunneling microscopy, we revealed a long-range ordered spin density wave (SDW) for the first time on a Cr (001) surface, corresponding to the well-known incommensurate SDW of bulk Cr. It displays a (~ 6.0 nm) long-period s
pin modulation in each (001) plane and an anti-phase behavior between adjacent planes, which are confirmed by changing the magnetization of the tip. Meanwhile, we simultaneously observed the coexisting charge density wave (CDW) with half the period of the SDW. Taking advantage of real-space measurement, we found the charge and spin modulations are in-phase, and their domain structures are highly correlated. Surprisingly, the phase of CDW in dI/dV map displays a {pi} shift around a density-of-states dip at about -22 meV, indicating an anomalous CDW gap opened below EF. These observations support that the CDW is a secondary order driven by SDW. Therefore, our work is not only the first real space characterization of incommensurate SDW, but also provide new insights on how SDW and CDW coexist.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
