University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Quantum control in silicon using coherent THz pulses

Lynch, SA, Thornton Greenland, P, Van Der Meer, AFG, Murdin, BN, Pidgeon, CR, Redlich, B, Vinh, NQ and Aeppli, G (2012) Quantum control in silicon using coherent THz pulses Proceedings of SPIE - The International Society for Optical Engineering, 8496.

Full text not available from this repository.

Abstract

It has long been known that shallow donors such as phosphorous and the other group-V elements, have a hydrogen-like optical spectrum. The main difference is that while the spectrum of atomic hydrogen lies in the visible band, the spectrum of shallow donors in silicon is downshifted to the THz frequency band. This is a direct consequence of the reduced Coulomb attraction seen by the loosely bound electron because the core electrons shield the positive donor atom nucleus, and because the electron is now moving in a dielectric material. While spectroscopy has already revealed much about the energy level structure, very little was known about the temporal dynamics of the system until now. We have used THz pulses from the FELIX free electron laser to probe these hydrogen-like levels. By exploiting the well-known pump-probe technique we have measured the characteristic lifetimes of the excited Rydberg states and found them to be of the order 200 ps. Then, by making subtle changes to the geometry of the pump-probe experimental setup we demonstrate the existence of a THz photon echo. The photon echo is a purely quantum phenomenon with no classical analogue, and it allows us to study the quantum state of the donor electron. We then show, using the photon echo, that it is possible to create a coherent superposition of the ground and excited state of the donor. Measuring the photon echo is important because it can also be used to measure a second important characteristic lifetime of the silicon-donor system, the phase decoherence time. © 2012 SPIE.

Item Type: Article
Authors :
NameEmailORCID
Lynch, SAUNSPECIFIEDUNSPECIFIED
Thornton Greenland, PUNSPECIFIEDUNSPECIFIED
Van Der Meer, AFGUNSPECIFIEDUNSPECIFIED
Murdin, BNb.murdin@surrey.ac.ukUNSPECIFIED
Pidgeon, CRUNSPECIFIEDUNSPECIFIED
Redlich, BUNSPECIFIEDUNSPECIFIED
Vinh, NQUNSPECIFIEDUNSPECIFIED
Aeppli, GUNSPECIFIEDUNSPECIFIED
Date : 1 December 2012
Identification Number : https://doi.org/10.1117/12.928571
Depositing User : Symplectic Elements
Date Deposited : 17 May 2017 12:46
Last Modified : 17 May 2017 15:06
URI: http://epubs.surrey.ac.uk/id/eprint/836690

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800