One of the most significant impediments to understand ultrafast spin-manipulation is that the experimentalists’ tools of choice – time-resolved magneto-optical Kerr effect (MOKE), magnetic circular dichroism (MCD), and angle-resolved photoemission spectroscopy (ARPES) - remain beyond the reach of ab-initio simulations for solids. A direct comparison between theory and experiment, the bedrock of progress in other branches of solid state physics, is therefore absent in the field of ultrafast spin manipulation. This project aims to rectify this by (i) developing an ab-initio theory of these experimental techniques, i.e., a theory of time-resolved MOKE, MCD, as well as a working theory for time-resolved (AR)PES and (ii) implementing this theory in a state-of-the-art time-dependent density functional theory (TDDFT) code. With these tools in hand the project then aims, in close collaboration with experiments, to (iii) elucidate the underlying physical mechanisms behind the ultrafast dynamics of spin and charge and, (iv), study and design new materials such as ferromagnetic/anti-ferromagnetic (FM/AFM), anti-ferromagnetic/non-magnetic (AFM/NM) and FM/NM interfaces with a view to control spin by light.

Publications (1^st Funding Period 2018 - 2021)

• Angular momentum redistribution in laser-induced demagnetization 
  J. K. Dewhurst, S. Shallcross, P. Elliott, S. Eisebitt, C. v. Korff Schmising, and S. Sharma 
  Phys. Rev. B 104, 054438 (2021)  - DOI: 10.1103/PhysRevB.104.054438

• Spin/valley coupled dynamics of electrons and holes at the MoS₂–MoSe₂ interface
  A. Kumar, D. Yagodkin, N. Stetzuhn, S. Kovalchuk, A. Melnikov, P. Elliott, S. Sharma, C. Gahl, and K. I. Bolotin 
  Nano Lett. 21, 7123 (2021)  - DOI: 10.1021/acs.nanolett.1c01538

• Manipulating magnons via ultrafast magnetization modulation 
  N. Singh, P. Elliott, J. K. Dewhurst, and S. Sharma  
  Phys. Rev. B 103, 134402 (2021)  - DOI: 10.1103/PhysRevB.103.134402

• Ultrafast optically induced ferromagnetic state in an elemental antiferromagnet 
  E. Golias, I. Kumberg, I. Gelen, S. Thakur, J. Gördes, R. Hosseinifar, Q. Guillet, J. K. Dewhurst, S. Sharma, C. Schüßler-Langeheine, N. Pontius, and W. Kuch 
  Phys. Rev. Lett. 126, 107202 (2021)  - DOI: 10.1103/PhysRevLett.126.107202

• Ab initio study of ultrafast charge dynamics in graphene 
  Q. Z. Li, P. Elliott, J. K. Dewhurst, S. Sharma, and S. Shallcross 
  Phys. Rev. B 103, L081102 (2021)  - DOI: 10.1103/PhysRevB.103.L081102

• Element-specific magnetization dynamics of complex magnetic systems probed by ultrafast magneto-optical spectroscopy 
  C. von Korff Schmising, F. Willems, S. Sharma, K. Yao, M. Borchert, M. Hennecke, D. Schick, I. Radu, C. Strüber, D. W. Engel, V. Shokeen, J. Buck, K. Bagschik, J. Viefhaus, G. Hartmann, B. Manschwetus, S. Grunewald, S. Düsterer, E. Jal, B. Vodungbo, J. Lüning, and S. Eisebitt 
  Appl. Sci. 10, 7580 (2020)  - DOI: 10.3390/app10217580

• Distinct spectral response in M-edge magnetic circular dichroism 
  K. Yao, F. Willems, C. von Korff Schmising, I. Radu, C. Strüber, D. Schick, D. Engel, A. Tsukamoto, J. K. Dewhurst, S. Sharma, and S. Eisebitt 
  Phys. Rev. B 102, 100405(R)  (2020)  - DOI: 10.1103/PhysRevB.102.100405

• Efficiency of ultrafast optically induced spin transfer in Heusler compounds 
  D. Steil, J. Walowski, F. Gerhard, T. Kiessling, D. Ebke, A. Thomas, T. Kubota, M. Oogane, Y. Ando, J. Otto, A. Mann, M. Hofherr, P. Elliott, J. K. Dewhurst, G. Reiss, L. Molenkamp, M. Aeschlimann, M. Cinchetti, M. Münzenberg, S. Sharma, and S. Mathias 
  Phys. Rev. Res. 2, 023199 (2020)  - DOI: 10.1103/PhysRevResearch.2.023199

• The microscopic origin of spin-orbit mediated spin-flips 
  P. Elliott, N. Singh, K. Krieger, E. K. U. Gross, S. Sharma, and J. K. Dewhurst
  J. Magn. Magn. Mater. 502, 166473 (2020)  - DOI: 10.1016/j.jmmm.2020.166473

• Element specificity of transient extreme ultraviolet magnetic dichroism 
  J. K. Dewhurst, F. Willems, P. Elliott, Q. Z. Li, C. von Korff Schmising, C. Strüber, D. W. Engel, S. Eisebitt, and S. Sharma
  Phys. Rev. Lett. 124, 077203 (2020)  - DOI: 10.1103/PhysRevLett.124.077203

• Optical inter-site spin transfer probed by energy and spin-resolved transient absorption spectroscopy
  F. Willems, C. v. Korff Schmising, C. Strüber, D. Schick, D. W. Engel, J. K. Dewhurst, P. Elliott, S. Sharma, and S. Eisebitt 
  Nat. Commun. 11: 871 (2020)  - DOI: 10.1038/s41467-020-14691-5

• Ultrafast optically induced spin transfer in ferromagnetic alloys 
  M. Hofherr, S. Häuser, J. K. Dewhurst, P. Tengdin, S. Sakshath, H. T. Nembach, S. T. Weber, J. M. Shaw, T. J. Silva, H. C. Kapteyn, M. Cinchetti, B. Rethfeld, M. M. Murnane, D. Steil, B. Stadtmüller, S. Sharma, M. Aeschlimann and S. Mathias 
  Sci. Adv. 6 : eaay8717 (2020)  - DOI: 10.1126/sciadv.aay8717

• Complete description of the magnetic ground state in spinel vanadates
  J. Krishna, N. Singh, S. Shallcross, J. K. Dewhurst, E. K. U. Gross, T. Maitra, and S. Sharma
  Phys. Rev. B 100, 081102(R) (2019)  - DOI: 10.1103/PhysRevB.100.081102

• Light-wave dynamic control of magnetism
  F. Siegrist, J. A. Gessner, M. Ossiander, C. Denker, Y.-P. Chang, M. C. Schröder, A. Guggenmos, Y. Cui, J. Walowski, U. Martens, J. K. Dewhurst, U. Kleineberg, M. Münzenberg, S. Sharma, and M. Schultze
  Nature 571, 240 (2019)  - DOI: 10.1038/s41586-019-1333-x

• Magneto-optical functions at the 3p resonances of Fe, Co, and Ni: Ab initio description and experiment
  F. Willems, S. Sharma, C. v. Korff Schmising, J. K. Dewhurst, L. Salemi, D. Schick, P. Hessing, C. Strüber, W. D. Engel, and S. Eisebitt
  Phys. Rev. Lett. 122, 217202 (2019) - DOI: 10.1103/PhysRevLett.122.217202

• Competing spin transfer and dissipation at Co/Cu(001) interfaces on femtosecond timescales
  J. Chen, U. Bovensiepen, A. Eschenlohr, T. Müller, P. Elliott, E. K. U. Gross, J. K. Dewhurst, and S. Sharma
  Phys. Rev. Lett 122, 067202 (2019)  - DOI: 10.1103/PhysRevLett.122.067202

• Real time scissor correction in TD-DFT
  C.-Y. Wang, P. Elliott, S. Sharma, and J. K. Dewhurst
  J. Phys.: Condens. Matter 31, 214002 (2019)  - DOI: 10.1088/1361-648X/ab048a

• Substrate-controlled ultrafast spin injection and demagnetization
  J. K. Dewhurst, S. Shallcross, E. K. U. Gross, and S. Sharma
  Phys. Rev. Applied 10, 044065 (2018)  - DOI: 10.1103/PhysRevApplied.10.0440