Towards full quantum-coherent control of coupled electron spins on a surface

Christoph Wolf

Center for Quantum Nanoscience
Institute for Basic Science, Ewha Womans University
Seoul, Korea

Tuesday, 30th May 2023,16:00 s.t.

The talk will be given in hybrid mode.

You can either attend in physical presence:
TU Wien, Institute of Applied Physics,
Wiedner Hauptstraße 8-10, 1040 Vienna
Yellow Tower “B”, Seminar Room DB 05 B (5th floor)

Or you join via Zoom:
Meeting ID: 960 6275 1637       Password: 9ANd8XWj

Towards full quantum-coherent control of coupled electron spins on a surface

In less than a decade since the first measurement of electron spin resonance (ESR) in a scanning tunneling microscope (STM), we have now achieved quantum-coherent control of individual electron spins on a surface [1,2].

In this talk, I first want to highlight a few aspects of the ESR-STM technique, such as the ability to distinguish different isotopes by identifying the nuclear spin, the high-precision determination of the electron ground state, and the measurement of exchange-coupling constants between individual molecular dimers [3,4,5].

In the second part of my talk, I will introduce a new paradigm in ESR-STM that has only emerged in the past two years: quantum coherent control. By utilizing the sub-atomic spatial precision of the STM, we are able to build structures of only a few atoms. Using the high energy resolution, we can then determine the interaction Hamiltonian and design quantum functionality in these structures. In our pioneering work [2], we have shown the possibility of quantum state control and quantum gate operations – in principle a quantum computer at the atomic scale.

[1] Baumann
et al., Science 350, 417 (2015)

[2] Phark et al., arXiv:2108.09880
[3] Kim et al., PRB 104 174408 (2021)
] Kim et al., Nano Letters 22 9766 (2022)
[5] Zhang et al., Nature Chemistry 14 59 (2022)