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Physics Department Colloquium: Prof Jascha Repp

Prof Jascha Repp (Universität Regensburg) will give a seminar on Thursday 7 March 2024.

  • 7 Mar 2024, 1.15pm to 7 Mar 2024, 2.15pm GMT
  • 8 West, 3.13, University of Bath
  • This event is free

The Department of Physics is delighted to welcome Prof Jascha Repp (Universität Regensburg) to give the third Physics Department Colloquium of Semester 2 2023/24. Please join us to listen to Prof Jascha Repp's seminar titled 'Accessing non-equilibrium at the intrinsic scales of molecules'.

A reception will be held directly after the seminar, where tea and coffee will be provided.

The seminar is open to anyone from the university, students are encouraged to attend.

Title

Accessing non-equilibrium at the intrinsic scales of molecules

Abstract

While scanning probe microscopy (SPM) has revolutionized our understanding of the atomistic world it is usually too slow to capture non-equilibrium excitation processes. Two complementary approaches that allow accessing non-equilibrium phenomena with SPM will be presented.

Accessing ultra-fast phenomena is enabled by combining lightwave electronics with scanning tunneling microscopy (STM), allowing for combined femtosecond and sub-angstrom resolution in observing matter (1). Lightwave STM also provides access in the control of matter by utilizing localized electric fields to exert atom-scale femtosecond forces (2). Further, we show how lightwave STM can be extended to its ultrafast spectroscopy variant (3). The corresponding ultrafast and atomically resolved tunnelling spectra reveal transient energy shifts of a single selenium vacancy in a WSe2 monolayer on gold. Another approach gives us access to intermediate timescales that are relevant for spin precession and relaxations. We exploit the high sensitivity of atomic force microscopy (AFM) to perform STM and spectroscopy on molecules in absence of any conductance of the underlying substrate. Thereby, we gain access to out-of-equilibrium charge states (4) that are out of reach for conventional STM. Extending this technique by electronic pump-probe spectroscopy, we measured the triplet lifetime of individual molecules and its quenching by nearby oxygen molecules (5). Combined with radio-frequency magnetic-field driving we introduce AFM-based electron spin resonance and spin manipulation showing long spin coherence in single molecules (6).

References:

  1. T. Cocker et al., Nature 539, 263 (2016).

  2. D. Peller et al., Nature 585, 58 (2020).

  3. C. Roelcke et al., in press (2023).

  4. L. L. Patera et al., Nature 566, 245 (2019).

  5. J. Peng et al., Science 373, 452 (2021).

  6. L. Sellies et al., Nature 624, 64 (2023).

Location

Please join us at our Claverton Down campus in 8 West 3.13.


8 West, 3.13 University of Bath Claverton Down Bath BA2 7AY United Kingdom

Contact Us

For any questions about the colloquium, please contact Dr Habib Rostami and Prof Kamal Asadi.