Imaging Quantum Phenomena by  Spin-Polarized Scanning Tunneling Microscopy

Session

Plenary Speaker

Authors

Professor Roland Wiesendanger (1)

Affiliations

1. Interdisciplinary Nanoscience Center Hamburg, University of Hamburg

Keywords

Spin-Polarized Scanning Tunneling Microscopy, SP-STM

Abstract text

The development of Spin-Polarized Scanning Tunneling Microscopy (SP-STM), as first reported 30 years ago [1], has led to unprecedented insight into spin-dependent quantum phenomena on the nanometer scale down to the single atom level [2]. This is due to the fact that SP-STM provides access to the spatial nature of the wavefunctions as well as the energy levels of quantum states combined with spin sensitivity at ultimate spatial, time and energy resolution. A beautiful example are quantum states of single spins interacting with a superconducting substrate or quantum confined states within superconducting vortices. Moreover, the combination of SP-STM with STM-based single atom manipulation techniques [3] has led to unique insight into the quantum behavior of artificially fabricated nanostructures [4] and even the demonstration of prototype all-spin atomic-scale logic devices [5]. Another impressive recent example are linear arrays of spins, realized by artificially constructed chains of magnetic atoms, interacting with a superconductor substrate. In this case, novel quantum phases can emerge, such as topological superconductivity, being a precursor to Majorana quasiparticles [6,7] which offer great potential for fault-tolerant topological quantum computation [8]. Such examples show the great importance and impact of quantum microscopy techniques for future quantum technologies based on novel kinds of hybrid quantum materials.   

References

[1]    R. Wiesendanger et al., Phys. Rev. Lett. 65, 247 (1990).

[2]    R. Wiesendanger, Rev. Mod. Phys. 81, 1495 (2009).

[3]    D. Serrate et al., Nature Nanotechnology 5, 350 (2010).

[4]    A. A. Khajetoorians et al., Nature Physics 8, 497 (2012).

[5]    A. A. Khajetoorians et al., Science 332, 1062 (2011).

[6]    S. Nadj-Perge et al., Phys. Rev. B 88, 20407 (2013).

[7]    H. Kim et al., Science Advances 4, eaar5251 (2018).

[8]    J. Alicea et al., Nature Phys. 7, 412 (2011).