scholarly journals Theory of spin-polarized angle-resolved photoemission spectroscopy of ferromagnetic nickel surfaces

1995 ◽  
Vol 51 (18) ◽  
pp. 12498-12505 ◽  
Author(s):  
A. Ishii ◽  
K. Yamada ◽  
T. Aisaka ◽  
T. Kraft
Keyword(s):  
Photoemission Spectroscopy ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Spin Polarized

Spin Polarized Photoemission from Fe On CU(100)

1991 ◽  
Vol 231 ◽  
Author(s):  
D.P. Pappas ◽  
K.-P. KÄmper ◽  
B.P. Miller ◽  
H. Hopster ◽  
D.E. Fowler ◽  
...  
Keyword(s):  
Low Energy ◽  
Photoemission Spectroscopy ◽  
Universal Curve ◽  
Exchange Splitting ◽  
Attenuation Length ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Minority Spin ◽  
Spin Polarized ◽  
The Difference ◽  
Majority Spin

AbstractThe spin resolved electronic structure of ultra-thin Fe films on Cu(100) was investigated using spin polarized angle resolved photoemission spectroscopy. All exchange splitting of the Fe ∆s band of 2.5 eV is observed for photon energies between 20 and 30 eV. ∆ peak at 6 eV binding energy which has been previously identified as a many-electron resonance was observed only after contamination of the films with oxygen. In addition, the spin dependent attenuation lengths for electrons in Fe were measured at 11, 19, and 40 eV above Ef. The attenuation length for the minority spin electrons was found to be shorter than that of the majority spin electrons. The difference between the two attenuation lengths was shown to increase at low energy. Short attenuation lengths of ≃3 monolayer were measured at II eV. The large increase of the attenuation length at low energy which is expected from the “universal curve” is not observed in Fe.

scholarly journals Magnetism-induced topological transition in EuAs3

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erjian Cheng ◽  
Wei Xia ◽  
Xianbiao Shi ◽  
Hongwei Fang ◽  
Chengwei Wang ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Nodal Line ◽  
Photoemission Spectroscopy ◽  
Topological Transition ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Spin Polarized ◽  
Lifshitz Transition ◽  
Antiferromagnetic Ground State ◽  
Exotic Physics ◽  
Topological Semimetals

AbstractThe nature of the interaction between magnetism and topology in magnetic topological semimetals remains mysterious, but may be expected to lead to a variety of novel physics. We systematically studied the magnetic semimetal EuAs3, demonstrating a magnetism-induced topological transition from a topological nodal-line semimetal in the paramagnetic or the spin-polarized state to a topological massive Dirac metal in the antiferromagnetic ground state at low temperature. The topological nature in the antiferromagnetic state and the spin-polarized state has been verified by electrical transport measurements. An unsaturated and extremely large magnetoresistance of ~2 × 105% at 1.8 K and 28.3 T is observed. In the paramagnetic states, the topological nodal-line structure at the Y point is proven by angle-resolved photoemission spectroscopy. Moreover, a temperature-induced Lifshitz transition accompanied by the emergence of a new band below 3 K is revealed. These results indicate that magnetic EuAs3 provides a rich platform to explore exotic physics arising from the interaction of magnetism with topology.

scholarly journals Evidence for a large Rashba splitting in PtPb4 from angle-resolved photoemission spectroscopy

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Kyungchan Lee ◽  
Daixiang Mou ◽  
Na Hyun Jo ◽  
Yun Wu ◽  
Benjamin Schrunk ◽  
...  
Keyword(s):  
Photoemission Spectroscopy ◽  
Angle Resolved Photoemission Spectroscopy

scholarly journals Observation of a singular Weyl point surrounded by charged nodal walls in PtGa

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
J.-Z. Ma ◽  
Q.-S. Wu ◽  
M. Song ◽  
S.-N. Zhang ◽  
E. B. Guedes ◽  
...  
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Photoemission Spectroscopy ◽  
Functional Theory ◽  
Fermi Arc ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Fermi Arcs ◽  
Surface Projection ◽  
Applicable Range ◽  
Opposite Chirality

AbstractConstrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on surfaces which connect the projections of the WPs with opposite chiral charges. However, this situation can be circumvented in the case of unpaired WP, without relevant surface Fermi arc connecting its surface projection, appearing singularly, while its Berry curvature field is absorbed by nontrivial charged nodal walls. Here, combining angle-resolved photoemission spectroscopy with density functional theory calculations, we show experimentally that a singular Weyl point emerges in PtGa at the center of the Brillouin zone (BZ), which is surrounded by closed Weyl nodal walls located at the BZ boundaries and there is no Fermi arc connecting its surface projection. Our results reveal that nontrivial band crossings of different dimensionalities can emerge concomitantly in condensed matter, while their coexistence ensures the net topological charge of different dimensional topological objects to be zero. Our observation extends the applicable range of the original Nielsen-Ninomiya no-go theorem which was derived from zero dimensional paired WPs with opposite chirality.

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