The physics and technology of low-dimensional electronic systems at terahertz frequencies
Lead Research Organisation:
University of Leeds
Department Name: Electronic and Electrical Engineering
Abstract
Over the last 20 years, the study of mesoscopic quantum-confined electronic systems has revealed a wealth of exciting and fundamental physics. These studies show no sign of abating as advances in device fabrication and measurement techniques enable ever more intricate structures and more sophisticated experiments to be made. The characteristic energy scale in many important mesoscopic devices such as two-dimensional electron systems, layered semiconductor structures, semiconductor quantum dots, and laterally-confined wires, dots, and other geometries, corresponds to the terahertz (THz) frequency range (1 THz = 1x10^12 Hz = 4.1 meV), which until recently has been difficult to access. Furthermore, although the majority of studies of mesoscopic systems use dc transport or optical (near-infrared) techniques, invaluable information on the states and dynamics of carriers in condensed matter systems, not obtainable by dc transport methods, can potentially be accessed though the dynamic (high frequency) electronic response. Our vision is to create a step-change in the study of mesoscopic electronic systems by developing and exploiting THz fre-quency technology, and in particular, guided-wave techniques, to probe the THz frequency / picosecond response of quantum-confined electronic systems. We will develop quasi-optical techniques to generate (and detect) single-cycle THz / picosecond electronic pulses adjacent to the mesoscopic system in the cryostat, avoiding the RC bandwidth-limiting problems inherent in previous high frequency (up to the gigahertz range) electrical measurements. We will also develop the methodology to perform picosecond-resolution measurements capable of monitoring the spatial position of single electrons three orders-of-magnitude faster than achieved previously; this will provide a generic technology for the field of mesoscopic physics where the onset of, or change in, a quantum state occurs on a picosecond time scale. This programme, which comprises the symbiotic development of THz frequency science and technology in quantum con-fined electronic systems, will be unique internationally and will open an important new direction for mesoscopic physics.
Organisations
Publications
Bacon DR
(2016)
Free-space terahertz radiation from a LT-GaAs-on-quartz large-area photoconductive emitter.
in Optics express
Burnett A
(2010)
Calculation of terahertz active normal modes in organic crystals
Burnett A
(2012)
Infrared and Raman Spectroscopy in Forensic Science
Burnett A
(2009)
Broadband terahertz time-domain spectroscopy of drugs-of-abuse and the use of principal component analysis
in The Analyst
Burnett AD
(2013)
Effect of molecular size and particle shape on the terahertz absorption of a homologous series of tetraalkylammonium salts.
in Analytical chemistry
Burnett AD
(2010)
Calculation and measurement of terahertz active normal modes in crystalline PETN.
in Chemphyschem : a European journal of chemical physics and physical chemistry
Byrne M
(2011)
Simultaneous measurement of orthogonal components of polarization in a free-space propagating terahertz signal using electro-optic detection
in Applied Physics Letters
Byrne M
(2008)
Terahertz vibrational absorption spectroscopy using microstrip-line waveguides
in Applied Physics Letters
Davies A.G.
(2010)
Terahertz imaging and spectroscopy
in EuCAP 2010 - The 4th European Conference on Antennas and Propagation
Dazhang L
(2009)
On-chip terahertz Goubau-line waveguides with integrated photoconductive emitters and mode-discriminating detectors
in Applied Physics Letters
Dean P
(2012)
Resonant-phonon depopulation terahertz quantum cascade lasers and their application in spectroscopic imaging
in Semiconductor Science and Technology
Dean P
(2011)
Measurement and analysis of the diffuse reflectance of powdered samples at terahertz frequencies using a quantum cascade laser.
in The Journal of chemical physics
Dodoo-Amoo NA
(2014)
Non-universality of scaling exponents in quantum Hall transitions.
in Journal of physics. Condensed matter : an Institute of Physics journal
Hargreaves M
(2009)
Comparison of near infrared laser excitation wavelengths and its influence on the interrogation of seized drugs-of-abuse by Raman spectroscopy
in Journal of Raman Spectroscopy
Hatem O
(2011)
Terahertz-frequency photoconductive detectors fabricated from metal-organic chemical vapor deposition-grown Fe-doped InGaAs
in Applied Physics Letters
Hunter N
(2015)
On-chip picosecond pulse detection and generation using graphene photoconductive switches.
in Nano letters
Mayorov A
(2014)
Surface acoustic wave generation and detection using graphene interdigitated transducers on lithium niobate
in Applied Physics Letters
Russell C
(2010)
Terahertz spectral measurements of a homologous organic series
Russell C
(2013)
Spectroscopy of polycrystalline materials using thinned-substrate planar Goubau line at cryogenic temperatures.
in Lab on a chip
Saeed K
(2011)
Impact of disorder on frequency scaling in the integer quantum Hall effect
in Physical Review B
Salih M
(2013)
Terahertz quantum cascade lasers with thin resonant-phonon depopulation active regions and surface-plasmon waveguides
in Journal of Applied Physics
Sydoruk O
(2015)
Terahertz plasmons in coupled two-dimensional semiconductor resonators
in Physical Review B
Wood C
(2013)
On-chip terahertz spectroscopic techniques for measuring mesoscopic quantum systems
in Review of Scientific Instruments
Wood C
(2010)
Terahertz emission from metal-organic chemical vapor deposition grown Fe:InGaAs using 830 nm to 1.55 µm excitation
in Applied Physics Letters
Wu J
(2015)
Excitation, detection, and electrostatic manipulation of terahertz-frequency range plasmons in a two-dimensional electron system.
in Scientific reports
Description | This project developed a novel technology for the sub-picosecond sampling of nanoscale condensed matter systems, at low temperatures and in high magnetic fields. The method developed uses fibre coupling of 100 fs laser pulses to both excite and detection terahertz frequency range radiation in the sample space of a dilution refrigerator, and led to the first picosecond pulsed measurements of confined plasmons in a 2DEG system. |
Exploitation Route | The project lead to an international patent for on-chip spectroscopy, with relevance to the pharmaceutical and defence sectors. The project provides a basis for the study of nanoscale systems in the terahertz frequency range, which can be exploited for the study of low dimensional semiconductors, nano magnetic (spin injection/detection) systems and picosecond switching devices. |
Sectors | Electronics,Pharmaceuticals and Medical Biotechnology |