Skip to ContentSkip to Navigation
About usNews and EventsNews articles

Quantum optical control of Donor-bound electron spins in GaAs

11 January 2011

PhD ceremony: Mr. M. Sladkov, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen

Title: Quantum optical control of Donor-bound electron spins in GaAs

Promotor(s): prof. C.H. van der Wal

Faculty: Mathematics and Natural Sciences


This thesis presents experimental research on coherent manipulation by laser light of the quantum state of an ensemble of electron spins in a solid. The medium is formed by donor-bound electron spins in GaAs. The coherent manipulation is achieved with a technique that was till now mostly explored with atomic vapors. Applying this to a donor-bound electron ensemble is possible at low temperature and low donor concentration, where neighboring electrons do not interact. Under these conditions, the electron ensembles and atomic vapors have similar properties. However, the solid-state medium has the advantage of easy integration with existing semiconductor technologies, and is thereby a more suitable system for quantum information technologies. Moreover, the rich interactions between the spins and their environment in GaAs make it an interesting system for exploring new physics. In order to control the electron spins with lasers at low temperature we built a dedicated experimental setup, which allows mechanical positioning of the sample in a helium cryostat with sub-micrometer precision. The laser light is delivered to the sample by an optical fiber. In a high magnetic field, we observed and controlled quantum phenomena that result in optical transparency for transitions that are addressed with a resonant laser. This gives access to a robust technique for controlling strong interactions between quantum optical signal fields and quantum states of spins. Our results thereby provide all the experimental techniques that are needed for future experiments on demonstrating the preparation of nonlocal quantum entanglement between spin excitations in two different ensembles.


Last modified:15 September 2017 3.41 p.m.

More news

  • 17 April 2019

    Why lightning often strikes twice

    In contrast to popular belief, lightning often does strike twice, but the reason why a lightning channel is ‘reused’ has remained a mystery. Now, an international research team led by the University of Groningen has used the LOFAR radio telescope to...

  • 16 April 2019

    Still going strong after four decades

    On March 29th professor of Applied Physics Jeff de Hosson was offered a farewell symposium, a few months after his official retirement date near the close of 2018. ‘But 29 March was the 100th birthday of Jan Francken, my predecessor.’ Besides, De Hosson...

  • 11 April 2019

    Ben Feringa in orbit around the Sun

    Dozens of minor planets that used to orbit the Sun anonymously were named by the International Astronomical Union on 6 April 2019. The asteroid that used to be known as ‘minor planet 12655’ was named after Prof. Ben Feringa, winner of the 2016 Nobel...