Dr.  Christoph Sürgers

Dr. Christoph Sürgers

  • Wolfgang Gaede Str. 1
    76131 Karlsruhe

Exploring materials for future spintronics

Magnetoelectronic transport properties of noncollinear antiferromagnets

Antiferromagnetic materials with a noncollinear magnetic structure play a vital role in the emerging field of antiferromagnetic spintronics. For instance, in contrast to what one might expect, these materials can exhibit a large anomalous Hall effect despite a tiny magnetization arising from an intrinsic property of the electronic band structure and from breaking certain symmetry relations. Currently, we are investigating the electronic transport properties and microwave absorption of various Mn-based compounds to unravel the coupling between the magnetic and crystalline structure under mechanical strain. 

Recently published:
Controlling Chiral Spin States of a Triangular‐Lattice Magnet by Cooling in a Magnetic Field. Deng, S.; Fischer, G.; Uhlarz, M.; Wosnitza, J.; Bohnen, K.; Heid, R.; Wang, C.; Sürgers, C. Advanced Functional Materials, 29, Article No.1900947 (2019). doi:10.1002/adfm.201900947

Spininjection and spinmanipulation in CMOS-compatible heterostructures

In this cooperative project between the Physikalische Institut (PHI) at KIT and the Institute of Semiconductortechnology (IHT) at the University of Stuttgart we aim to demonstrate spininjection, -detection and –manipulation in CMOS-compatible devices. The project was supported by the Deutsche Forschungsgemeinschaft (DFG) until 2020 and is being continued further. Recently, we investigated the anomalous Nernst effect of Mn5Ge3Cx films on sapphire and Ge substrates demonstrating a strong increase of the anomalous Nernst effect due to C incorporation.

Recently published:
Anomalous Nernst effect of a ferromagnetic film on a semiconductor. Deng, S.; Kraft, R.; Fischer, G.; Sürgers, C. Appl. Phys. Lett. 117, 262402 (2020). https://doi.org/10.1063/5.0033683
Magnetic characterization of a Mn based ferromagnet on SixGe(1-x-y)Sny with high Sn content. Funk, H. S.; Kern, M.; Weisshaupt, D.; Sürgers, C.; Fischer, I.; Oehme, M.; van Slageren, J.; Schulze, J. ECS transactions, 93, 101 (2019). doi:10.1149/09301.0101ecst

Detecting mechanical strain by NV-center spectroscopy

LogoWe propose to implement a new experimental technique based on optically detected nitrogen-vacancy (NV) color centers in diamond. We will extend this method by application to two-phase heterostructures comprising a metallic thin film deposited on a diamond membrane containing NV centers located close to the film/membrane interface. By this approach we will be able to sense the local intrinsic strain of the film by optical read-out of the NV-center energy states. The power of this method will be demonstrated by investigating metallic antiferromagnets with non-collinear spin arrangements currently investigated in our group. The project is part of the collaborative research center TRR288 "Elastic Tuning and Response of Quantum Phases of Matter" (Frankfurt - Karlsruhe - Mainz) supported by the DFG since 2020.



For further information about this research and working with us please contact Christoph Sürgers.

Experimental methods

  • Thin film and multilayer deposition (various methods)
  • Electron diffraction, x-ray diffraction, magneto-optical spectroscopy, scanning probe microscopy
  • Electronic transport measurements (resistivity, Hall effect, Nernst effect, electric-field effect) at low temperatures and in magnetic fields

Current collaborations

Christoph Sürgers

Researcher ID-2873-2013

Publications of the last five years

Composition and magnetic properties of thin films grown by interdiffusion of Mn and Sn-Rich, Ge lattice matched SixGe1-x-ySny layers
Funk, H. S.; Kern, M.; Weißhaupt, D.; Sürgers, C.; Fischer, I. A.; Oehme, M.; Slageren, J. van; Schulze, J.
2022. Journal of magnetism and magnetic materials, 546, Art.-Nr.: 168731. doi:10.1016/j.jmmm.2021.168731
Weak localization and weak antilocalization in doped Ge1-ySny layers with up to 8% Sn
Weißhaupt, D.; Funk, H. S.; Kern, M.; Dettling, M. M.; Schwarz, D.; Oehme, M.; Sürgers, C.; Slageren, J. van; Fischer, I. A.; Schulze, J.
2021. Journal of physics / Condensed matter, 33 (8), 085703. doi:10.1088/1361-648X/abcb68
Resolving the spin polarization and magnetic domain wall width of (Nd,Dy)FeB with spin-polarized scanning tunneling microscopy
Miyamachi, T.; Sürgers, C.; Wulfhekel, W.
2021. Applied physics express. Letter, 14 (11), Art.Nr. 115504. doi:10.35848/1882-0786/ac2a56
Anomalous Nernst effect of a ferromagnetic film on a semiconductor
Deng, S.; Kraft, R.; Fischer, G.; Sürgers, C.
2020. Applied physics letters, 117 (26), 262402. doi:10.1063/5.0033683
Anomalous Nernst effect in ferromagnetic MnGeC thin films on insulating sapphire
Kraft, R.; Srichandan, S.; Fischer, G.; Sürgers, C.
2020. Journal of applied physics, 128 (3), 033905. doi:10.1063/5.0014815
Onset of phase diffusion in high kinetic inductance granular aluminum micro-SQUIDs
Friedrich, F.; Winkel, P.; Borisov, K.; Seeger, H.; Sürgers, C.; Pop, I. M.; Wernsdorfer, W.
2019. Superconductor science and technology, 32 (12), 125008. doi:10.1088/1361-6668/ab4918
Magnetic characterization of a Mn based ferromagnet on SixGe(1-x-y)Sny with high Sn content
Funk, H. S.; Kern, M.; Weisshaupt, D.; Sürgers, C.; Fischer, I.; Oehme, M.; Slageren, J. van; Schulze, J.
2019. ECS transactions, 93 (1), 101–104. doi:10.1149/09301.0101ecst
Controlling Chiral Spin States of a Triangular‐Lattice Magnet by Cooling in a Magnetic Field
Deng, S.; Fischer, G.; Uhlarz, M.; Wosnitza, J.; Bohnen, K.-P.; Heid, R.; Wang, C.; Sürgers, C.
2019. Advanced functional materials, 29 (37), Article No.1900947. doi:10.1002/adfm.201900947
Creation of equal-spin triplet superconductivity at the Al/EuS interface
Diesch, S.; Machon, P.; Wolz, M.; Sürgers, C.; Beckmann, D.; Belzig, W.; Scheer, E.
2018. Nature Communications, 9 (1), Article no 5248. doi:10.1038/s41467-018-07597-w
Phase separation and zero thermal expansion in antiperovskite Mn₃ZnMnN : An in situ neutron diffraction investigation
Deng, S.; Sun, Y.; Wu, H.; Shi, Z.; Wang, L.; Yan, J.; Shi, K.; Hu, P.; Diao, X.; Huang, Q.; Sürgers, C.; Wang, C.
2018. Scripta materialia, 146, 18–21. doi:10.1016/j.scriptamat.2017.10.031
Electrical switching of the anomalous Hall effect
Sürgers, C.
2018. Nature Electronics, 1, 154–155, Nature Research. doi:10.1038/s41928-018-0047-7
Local Joule Heating Mimicking Electroresistance-Like Behavior in Antiperovskite Mn3GaC
Deng, S.; Fischer, G.; Srichandan, S.; Wang, L.; Wang, C.; Sürgers, C.
2018. Advanced electronic materials, 4 (9), Art.-Nr.:1800028/1–6. doi:10.1002/aelm.201800028
Signature of f-electron conductance in α-Cer single-atom contacts
Kuntz, S.; Berg, O.; Sürgers, C.; Löhneysen, H. von
2017. Physical review / B, 96, 085120. doi:10.1103/PhysRevB.96.085120
Quasi-metallic behavior of ZnO grown by atomic layer deposition : The role of hydrogen
Beh, H.; Hiller, D.; Bruns, M.; Welle, A.; Becker, H.-W.; Berghoff, B.; Sürgers, C.; Merz, R.; Zacharias, M.
2017. Journal of applied physics, 122 (2), Art. Nr. 025306. doi:10.1063/1.4994175
Thermoelectric effects in superconductor-ferromagnet tunnel junctions on europium sulfide
Kolenda, S.; Sürgers, C.; Fischer, G.; Beckmann, D.
2017. Physical review / B, 95 (22), Art. Nr. 224505. doi:10.1103/PhysRevB.95.224505
15 cm-1 to 12 000 cm-1 spectral coverage without changing optics: Diamond beam splitter adaptation of an FTIR spectrometer
Strelnikov, D.; Kern, B.; Sürgers, C.; Kappes, M. M.
2017. Review of scientific instruments, 88 (2), 023118. doi:10.1063/1.4976744
Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet
Sürgers, C.; Wolf, T.; Adelmann, P.; Kittler, W.; Fischer, G.; Löhneysen, H. von
2017. Scientific reports, 7, Art.Nr.: 42982. doi:10.1038/srep42982
Two-band superconductivity of bulk and surface states in Ag thin films on Nb
Tomanic, T.; Schackert, M.; Wulfhekel, W.; Sürgers, C.; Löhneysen, H. v.
2016. Physical review / B, 94 (22), Art.Nr.: 220503. doi:10.1103/PhysRevB.94.220503
Controlled electromigration and oxidation of free-standing copper wires
Hauser, J. S.; Schwichtenberg, J.; Marz, M.; Sürgers, C.; Seiler, A.; Gerhards, U.; Messerschmidt, F.; Hensel, A.; Dittmeyer, R.; Löhneysen, H. v.; Hoffmann-Vogel, R.
2016. Applied physics / A, 122, 1068. doi:10.1007/s00339-016-0600-z
Magnetostrictive Fe_73Ga_27 nanocontacts for low-field conductance switching
Kannan, U. M.; Kuntz, S.; Berg, O.; Kittler, W.; Basumatary, H.; Chelvane, J. A.; Sürgers, C.; Jammalamadaka, S. N.
2016. Applied physics letters, 108, Art. Nr. 242408. doi:10.1063/1.4953873
Second-Harmonic Generation from ZnO/Al2O3 Nanolaminate Optical Metamaterials Grown by Atomic-Layer Deposition
Wickberg, A.; Kieninger, C.; Sürgers, C.; Schlabach, S.; Mu, X.; Koos, C.; Wegener, M.
2016. Advanced optical materials, 4 (8), 1203–1208. doi:10.1002/adom.201600200
Anomalous Hall effect in the noncollinear antiferromagnet Mn5Si3
Sürgers, C.; Kittler, W.; Wolf, T.; Löhneysen, H. von
2016. AIP Advances, 6 (5), Art. Nr.: 055604. doi:10.1063/1.4943759
Remote control of magnetostriction-based nanocontacts at room temperature
Jammalamadaka, S. N.; Kuntz, S.; Berg, O.; Kittler, W.; Kannan, U. M.; Chelvane, J. A.; Sürgers, C.
2015. Scientific Reports, 5, 13621. doi:10.1038/srep13621
Large topological Hall effect in the non-collinear phase of an antiferromagnet
Sürgers, C.; Fischer, G.; Winkel, P.; Löhneysen, H. von
2014. Nature Communications, 5, Art.Nr. 3400. doi:10.1038/ncomms4400
Fabrication and magnetic characterization of nanometer-sized ellipses of the ferromagnetic insulator EuS
Wolf, M. J.; Sürgers, C.; Fischer, G.; Scherer, T.; Beckmann, D.
2014. Journal of magnetism and magnetic materials, 368 (November), 49–53. doi:10.1016/j.jmmm.2014.04.067
Magnetotransport in ferromagnetic Mn₅Ge₃, Mn₅Ge₃C₀̣₈ and Mn₅Si₃C₀̣₈ thin films
Sürgers, C.; Fischer, G.; Winkel, P.; Löhneysen, H. von
2014. Physical review / B, 90 (10), Art.Nr. 104421. doi:10.1103/PhysRevB.90.104421
Spin-polarized quasiparticle transport in exchange-split superconducting aluminum on europium sulfide
Wolf, M. J.; Sürgers, C.; Fischer, G.; Beckmann, D.
2014. Physical review / B, 90 (14), Art.Nr. 144509. doi:10.1103/PhysRevB.90.144509
Hanle-effect measurements of spin injection from Mn5Ge3C0.8/Al2O3-contacts into degenerately doped Ge channels on Si
Fischer, I. A.; Chang, L.-T.; Sürgers, C.; Rolseth, E.; Reiter, S.; Stefanov, S.; Chiussi, S.; Tang, J.; Wang, K. L.; Schulze, J.
2014. Applied Physics Letters, 105 (22), Article Nr. 222408. doi:10.1063/1.4903233
Temperature-dependent scanning tunneling spectroscopy on the Si(557)-Au surface
Sauter, M.; Hoffmann, R.; Sürgers, C.; Löhneysen, H. von
2014. Physical review / B, 89 (7), Art.Nr. 075406. doi:10.1103/PhysRevB.89.075406