A new spin- and angle-resolved inverse photoemission setup with a low-energy electron source is presented. The spin-polarized electron source, with a compact design, can decouple the spin polarization vector from the electron beam propagation vector, allowing one to explore any spin orientation at any wavevector in angle-resolved inverse photoemission. The beam polarization can be tuned to any preferred direction with a shielded electron optical system, preserving the parallel beam condition. We demonstrate the performances of the setup by measurements on Cu(001) and Au(111). We estimate the energy resolution of the overall system at room temperature to be ∼170 meV from kBTeff of a Cu(001) Fermi level, allowing a direct comparison to photoemission. The spin-resolved operation of the setup has been demonstrated by measuring the Rashba splitting of the Au(111) Shockley surface state. The effective polarization of the electron beam is P = 30% ± 3%, and the wavevector resolution is ΔkF ≲ 0.06 Å−1. Measurements on the Au(111) surface state demonstrate how the electron beam polarization direction can be tuned in the three spatial dimensions. The maximum of the spin asymmetry is reached when the electron beam polarization is aligned with the in-plane spin polarization of the Au(111) surface state.
REFERENCES
1.
S.
LaShell
, B. A.
McDougall
, and E.
Jensen
, “Spin splitting of an Au(111) surface state band observed with angle resolved photoelectron spectroscopy
,” Phys. Rev. Lett.
77
, 3419
(1996
).2.
M.
Hoesch
, M.
Muntwiler
, V. N.
Petrov
, M.
Hengsberger
, L.
Patthey
, M.
Shi
, M.
Falub
, T.
Greber
, and J.
Osterwalder
, “Spin structure of the Shockley surface state on Au (111)
,” Phys. Rev. B
69
, 241401
(2004
).3.
M.
Hochstrasser
, J. G.
Tobin
, E.
Rotenberg
, and S. D.
Kevan
, “Spin-resolved photoemission of surface states of W(110)-(1 × 1)H
,” Phys. Rev. Lett.
89
, 216802
(2002
).4.
Yu. M.
Koroteev
, G.
Bihlmayer
, J. E.
Gayone
, E. V.
Chulkov
, S.
Blügel
, P. M.
Echenique
, and Ph.
Hofmann
, “Strong spin-orbit splitting on Bi surfaces
,” Phys. Rev. Lett.
93
, 046403
(2004
).5.
K.
Sugawara
, T.
Sato
, S.
Souma
, T.
Takahashi
, M.
Arai
, and T.
Sasaki
, “Fermi surface and anisotropic spin-orbit coupling of Sb(111) studied by angle-resolved photoemission spectroscopy
,” Phys. Rev. Lett.
96
, 046411
(2006
).6.
I. M.
Miron
, K.
Garello
, G.
Gaudin
, P.-J.
Zermatten
, M. V.
Costache
, S.
Auffret
, S.
Bandiera
, B.
Rodmacq
, A.
Schuhl
, and P.
Gambardella
, “Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection
,” Nature
476
, 189
(2011
).7.
Y.
Fan
and K. L.
Wang
, Spintronics Based on Topological Insulators
(World Scientific
, 2016
), Vol. 6, p. 1640001
.8.
T.
Yokoyama
and S.
Murakami
, “Spintronics and spincaloritronics in topological insulators
,” Physica E
55
, 1
–8
(2014
).9.
M. Z.
Hasan
and C. L.
Kane
, “Colloquium: Topological insulators
,” Rev. Mod. Phys.
82
, 3045
(2010
).10.
X.-L.
Qi
and S.-C.
Zhang
, “Topological insulators and superconductors
,” Rev. Mod. Phys.
83
, 1057
(2011
).11.
S.
Sanvito
, “Molecular spintronics: The rise of spinterface science
,” Nat. Phys.
6
, 562
(2010
).12.
C.
Barraud
, P.
Seneor
, R.
Mattana
, S.
Fusil
, K.
Bouzehouane
, C.
Deranlot
, P.
Graziosi
, L.
Hueso
, I.
Bergenti
, V.
Dediu
et al, “Unravelling the role of the interface for spin injection into organic semiconductors
,” Nat. Phys.
6
, 615
–620
(2010
).13.
M.
Cinchetti
, V. A.
Dediu
, and L. E.
Hueso
, “Activating the molecular spinterface
,” Nat. Mater.
16
, 507
(2017
).14.
T.
Duden
and E.
Bauer
, J. Electron Microsc.
47
, 379
(1998
).15.
N.
Rougemaille
and A. K.
Schmid
, Eur. Phys. J.: Appl. Phys.
50
, 20101
(2010
).16.
A.
Quesada
, G.
Chen
, A. T.
N'Diaye
, P.
Wang
, Y. Z.
Wu
, and A. K.
Schmid
, J. Mater. Chem. C
9
, 2801
(2021
).17.
V.
Dose
, “Ultraviolet Bremsstrahlung spectroscopy
,” Prog. Surf. Sci.
13
, 225
–283
(1983
).18.
N. V.
Smith
, “Inverse photoemission
,” Rep. Prog. Phys.
51
, 1227
(1988
).19.
F. J.
Himpsel
, “Inverse photoemission from semiconductors
,” Surf. Sci. Rep.
12
, 3
–48
(1990
).20.
J. E.
Ortega
and F. J.
Himpsel
, “Quantum well states as mediators of magnetic coupling in superlattices
,” Phys. Rev. Lett.
69
, 844
–847
(1992
).21.
M.
Skibowski
and L.
Kipp
, “Inverse combined with direct photoemission: Momentum resolved electronic structure of 2D systems
,” J. Electron Spectrosc. Relat. Phenom.
68
, 77
–96
(1994
).22.
J.-M.
Themlin
, I.
Forbeaux
, V.
Langlais
, H.
Belkhir
, and J.-M.
Debever
, “Unoccupied surface state on the () R30° of 6H-SiC(0001)
,” Europhys. Lett.
39
, 61
(1997
).23.
M.
Donath
, “Spin-resolved inverse photoemission of ferromagnetic surfaces
,” Appl. Phys. A
49
, 351
(1989
).24.
M.
Budke
, T.
Allmers
, M.
Donath
, and G.
Rangelov
, “Combined experimental setup for spin-and angle-resolved direct and inverse photoemission
,” Rev. Sci. Instrum.
78
, 113909
(2007
).25.
M.
Cantoni
and R.
Bertacco
, “High efficiency apparatus for spin polarized inverse photoemission
,” Rev. Sci. Instrum.
75
, 2387
–2392
(2004
).26.
S. D.
Stolwijk
, H.
Wortelen
, A. B.
Schmidt
, and M.
Donath
, “Rotatable spin-polarized electron source for inverse-photoemission experiments
,” Rev. Sci. Instrum.
85
, 013306
(2014
).27.
S. N. P.
Wissing
, A. B.
Schmidt
, H.
Mirhosseini
, J.
Henk
, C. R.
Ast
, and M.
Donath
, “Ambiguity of experimental spin information from states with mixed orbital symmetries
,” Phys. Rev. Lett.
113
, 116402
(2014
).28.
S. D.
Stolwijk
, K.
Sakamoto
, A. B.
Schmidt
, P.
Krüger
, and M.
Donath
, Phys. Rev. B
91
, 245420
(2015
).29.
C.
Datzer
, A.
Zumbülte
, J.
Braun
, T.
Förster
, A. B.
Schmidt
, J.
Mi
, B.
Iversen
, P.
Hofmann
, J.
Minár
, H.
Ebert
et al, “Unraveling the spin structure of unoccupied states in Bi2Se3
,” Phys. Rev. B
95
, 115401
(2017
).30.
P.
Eickholt
, C.
Sanders
, M.
Dendzik
, L.
Bignardi
, D.
Lizzit
, S.
Lizzit
, A.
Bruix
, P.
Hofmann
, and M.
Donath
, “Spin structure of K valleys in single-layer WS2 on Au(111)
,” Phys. Rev. Lett.
121
, 136402
(2018
).31.
G.
Berti
, A.
Calloni
, A.
Brambilla
, G.
Bussetti
, L.
Duò
, and F.
Ciccacci
, “Direct observation of spin-resolved full and empty electron states in ferromagnetic surfaces
,” Rev. Sci. Instrum.
85
, 073901
(2014
).32.
F.
Ciccacci
, S.
De Rossi
, E.
Pelucchi
, and A.
Tagliaferri
, “Spin-resolved electron spectroscopy with highly polarized sources: Inverse photoemission from ferromagnets
,” Rev. Sci. Instrum.
68
, 1841
(1997
).33.
M. S.
Jagadeesh
, A.
Calloni
, G.
Bussetti
, L.
Duò
, and F.
Ciccacci
, “Spin-resolved PES and IPES investigation of the graphene/Ni(111) interface
,” Phys. Status Solidi B
255
, 1700415
(2017
).34.
T.
Duden
and E.
Bauer
, “A compact electron-spin-polarization manipulator
,” Rev. Sci. Instrum.
66
, 2861
–2864
(1995
).35.
V.
Dose
, “VUV isochromat spectroscopy
,” Appl. Phys.
14
, 117
–118
(1977
).36.
C.
Thiede
, A. B.
Schmidt
, and M.
Donath
, “Optimizing the performance of bandpass photon detectors for inverse photoemission: Transmission of alkaline earth fluoride window crystals
,” Rev. Sci. Instrum.
86
, 085101
(2015
).37.
C.
Thiede
, I.
Niehues
, A. B.
Schmidt
, and M.
Donath
, “The acetone bandpass detector for inverse photoemission: Operation in proportional and Geiger–Müller modes
,” Meas. Sci. Technol.
29
, 065901
(2018
).38.
J. J.
Scheer
and J.
van Laar
, “GaAs-Cs: A new type of photoemitter
,” Solid State Commun.
3
, 189
–193
(1965
).39.
D. T.
Pierce
, F.
Meier
, and P.
Zürcher
, “Negative electron affinity GaAs: A new source of spin-polarized electrons
,” Appl. Phys. Lett.
26
, 670
–672
(1975
).40.
D. T.
Pierce
and F.
Meier
, “Photoemission of spin-polarized electrons from GaAs
,” Phys. Rev. B
13
, 5484
(1976
).41.
D. T.
Pierce
, R. J.
Celotta
, G. C.
Wang
, W. N.
Unertl
, A.
Galejs
, C. E.
Kuyatt
, and S. R.
Mielczarek
, “The GaAs spin polarized electron source
,” Rev. Sci. Instrum.
51
, 478
–499
(1980
).42.
J.
Guo
and W.
Qu
, “Quantum efficiency conversion from the reflection-mode GaAs photocathode to the transmission-mode one
,” Optik
124
, 4012
–4015
(2013
).43.
F.
Ciccacci
and G.
Chiaia
, “Comparative study of the preparation of negative electron affinity GaAs photocathodes with O2 and with NF3
,” J. Vac. Sci. Technol., A
9
, 2991
–2995
(1991
).44.
R. L.
Sheffield
, “High brightness electron sources
,” in Proceedings of the Particle Accelerator Conference
(IEEE
, 1995
), Vol. 2, pp. 882
–886
.45.
H.
Boersch
, “Experimentelle bestimmung der energieverteilung in thermisch ausgelösten elektronenstrahlen
,” Z. Phys.
139
, 115
–146
(1954
).46.
H. J.
Meister
, “Die bewegung des polarisationsvektors eines Dirac-teilchens im makroskopischen elektromagnetischen feld
,” Z. Phys.
166
, 468
–476
(1962
).47.
M.
Maniraj
and S. R.
Barman
, “Influence of the contact potential and space-charge effect on the performance of a Stoffel-Johnson design electron source for inverse photoemission spectroscopy
,” Rev. Sci. Instrum.
85
, 033301
(2014
).48.
N. G.
Stoffel
and P. D.
Johnson
, “A low-energy high-brightness electron gun for inverse photoemission
,” Nucl. Instrum. Methods Phys. Res., Sect. A
234
, 230
–234
(1985
).49.
J. A.
Nelder
and R.
Mead
, “A simplex method for function minimization
,” Comput. J.
7
, 308
–313
(1965
).50.
M.
Budke
, V.
Renken
, H.
Liebl
, G.
Rangelov
, and M.
Donath
, “Inverse photoemission with energy resolution better than 200 MeV
,” Rev. Sci. Instrum.
78
, 083903
(2007
).51.
D.
Straub
and F. J.
Himpsel
, “Identification of image-potential surface states on metals
,” Phys. Rev. Lett.
52
, 1922
(1984
).52.
M.
Donath
, M.
Glöbl
, B.
Senftinger
, and V.
Dose
, “Photon polarization effects in inverse photoemission from Cu(001)
,” Solid State Commun.
60
, 237
–240
(1986
).53.
W. A.
Royer
and N. V.
Smith
, “Refracting instrument for ultraviolet inverse photoemission spectroscopy
,” Rev. Sci. Instrum.
59
, 737
–740
(1988
).54.
R.
Stiepel
, R.
Ostendorf
, C.
Benesch
, and H.
Zacharias
, “Vacuum ultraviolet photon detector with improved resolution for inverse photoemission spectroscopy
,” Rev. Sci. Instrum.
76
, 063109
(2005
).55.
P.
Marchand
and L.
Marmet
, “Binomial smoothing filter: A way to avoid some pitfalls of least-squares polynomial smoothing
,” Rev. Sci. Instrum.
54
, 1034
–1041
(1983
).56.
J.
Henk
, M.
Hoesch
, J.
Osterwalder
, A.
Ernst
, and P.
Bruno
, “Spin–orbit coupling in the L-gap surface states of Au(111): Spin-resolved photoemission experiments and first-principles calculations
,” J. Phys.: Condens. Matter
16
, 7581
(2004
).57.
F.
Reinert
and G.
Nicolay
, “Influence of the herringbone reconstruction on the surface electronic structure of Au(111)
,” Appl. Phys. A
78
, 817
–821
(2004
).58.
S. N. P.
Wissing
, C.
Eibl
, A.
Zumbülte
, A. B.
Schmidt
, J.
Braun
, J.
Minár
, H.
Ebert
, and M.
Donath
, “Rashba-type spin splitting at Au(111) beyond the Fermi level: The other part of the story
,” New J. Phys.
15
, 105001
(2013
).59.
A.
Zumbülte
, A. B.
Schmidt
, and M.
Donath
, “Momentum resolution in inverse photoemission
,” Rev. Sci. Instrum.
86
, 013908
(2015
).60.
D. P.
Woodruff
, W. A.
Royer
, and N. V.
Smith
, “Empty surface states, image states, and band edge on Au(111)
,” Phys. Rev. B
34
, 764
(1986
).61.
E.
Pelucchi
, S.
De Rossi
, and F.
Ciccacci
, “Spin polarized photoemission from thin GaAs photocathodes
,” J. Electron Spectrosc. Relat. Phenom.
76
, 505
–509
(1995
).62.
M.
Erbudak
and B.
Reihl
, “Depolarization of photoelectrons emitted from optically pumped GaAs
,” Appl. Phys. Lett.
33
, 584
–585
(1978
).63.
S.
Spezia
, D. P.
Adorno
, N.
Pizzolato
, and B.
Spagnolo
, “Temperature dependence of spin depolarization of drifting electrons in n-type GaAs bulks
,” Acta Phys. Pol., B
41
, 1171
(2010
).64.
R.
Allenspach
, F.
Meier
, and D.
Pescia
, “Spin polarized photoemission from GaAs and Ge: Temperature dependence of the threshold polarization
,” Appl. Phys. Lett.
44
, 1107
–1109
(1984
).65.
C.
Tusche
, A.
Krasyuk
, and J.
Kirschner
, “Spin resolved bandstructure imaging with a high resolution momentum microscope
,” Ultramicroscopy
159
, 520
–529
(2015
).66.
J. C.
Slonczewski
, J. Magn. Magn. Mater.
159
, L1
(1996
).67.
J. C.
Slonczewski
, J. Magn. Magn. Mater.
195
, L261
(1999
).68.
M.
Stiles
and A.
Zangwill
, Phys. Rev. B
66
, 014407
(2002
).69.
S. D.
Stolwijk
, A. B.
Schmidt
, M.
Donath
, K.
Sakamoto
, and P.
Krüger
, Phys. Rev. Lett.
111
, 176402
(2013
).© 2022 Author(s). Published under an exclusive license by AIP Publishing.
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