skip to content

Semiconductor Physics Group



David Ritchie is Professor of Experimental Physics and a Fellow of Robinson College in Cambridge. He is also Professor of Semiconductor Science and Technology at Swansea University. He received his first degree, in physics, from the University of Oxford in 1980 and his D Phil from the University of Sussex in 1986 studying the physics of mixtures of liquid 3He and 4He at milli-kelvin temperatures. Since then he has been working on III-V semiconductor physics and has extensive experience of the growth, fabrication and measurement of low dimensional electronic and optical structures. He has been co-author of over 1200 papers and was awarded the 2008 Tabor medal and prize by the UK Institute of Physics for distinguished research in surface or nanoscale physics. Watford Grammar School for Boys 1970-1977 MA in physics Hertford College, University of Oxford 1977-1980. D Phil in low temperature liquid helium physics, University of Sussex 1980-1985 Research Assistant, University of Sussex 1984-1985 Research Assistant/Associate, University of Cambridge 1985-1991 Toshiba Assistant Director of Research, University of Cambridge 1991-1999 Fellow of Robinson College, University of Cambridge 1991- Reader in Experimental Physics, University of Cambridge 1999-2002 Professor of Experimental Physics, University of Cambridge 2002- Fellow of the Institute of Physics 2005- Head of Semiconductor Physics Group, Cavendish Laboratory 2007-2018 Deputy Head of Department of Physics (Teaching) 2009-2013 Professor of Semiconductor Science and Technology, Swansea University 2018- Fellow of the Learned Society of Wales 2020-


The physics and technology of III-V semiconductors including:

  • Molecular beam epitaxy
  • Device processing, fabrication and testing
  • Low temperature electrical transport and optical measurements
  • Regrowth techniques
  • Very high mobility two-dimensional electron and hole gases 
  • Interactions between two-dimensional electron and hole gases
  • Quantum point contacts and quantum dots
  • THz devices and systems
  • THz quantum cascade lasers
  • Self-assembled InAs quantum dots
  • Single and entangled photon sources
  • Single photon detectors

Research Grants:

  • “Quantum light-emitting diode for secure communications” (Q-LED)” EPSRC/DTI LINK 7/4/2003 to 21/4/2006.
  • “The development of far-infrared quantum cascade lasers” EPSRC 1/4/2003 to 31/3/2006.
  • “Active Terahertz Imaging for Security - Detection of Threats, Explosives, Pathogens and Chemicals (TERASEC)” EU 1/1/2005 to 31/12/2006.
  • “Physics of Inter-subband Semiconductor Emitters (POISE)” EU 1/10/2004-30/9/2007.
  • “Novel terahertz, sensing and Imaging systems for biotechnology, healthcare and process monitoring (TERANOVA)” EU 1/10/2004 to 30/9/2007.
  • “Long wavelength, ultra-low threshold current THz Quantum Cascade Lasers” DTI 1/9/2005 to 31/8/2007.
  • “Remote sensing and detection of explosives using a terahertz camera” DTI 1/3/2005 to 29/2/2008.
  • “Development of a Global Network for Secure Communication based on Quantum cryptography (SECOQC)” EU 1/4/2004 to 30/9/2008.
  • “Mode locking of THz quantum cascade lasers” EPSRC 1/7/2006 to 30/3/2009.
  • “Quantum information processing IRC” EPSRC 1/4/2004 to 31/12/2009.
  • “Physics and technology of Semiconductor Quantum Nanostructures”  EPSRC 1/10/2005-28/2/2010.
  • “Deterministic single quantum dot nano-sources of entangled photon pairs (NanoEPR)” Nanoscience Europe1/7/2007-30/6/2010.
  • “Search for non-Abelian quantal phases and statistics” EPSRC 10/12/2009-9/10/2010
  • “Femtosecond Semiconductor Lasers” EPSRC 1/12/2009-30/12/2012.
  • “Electron-Hole Bilayers: Excitonic Phases and Collective Modes” EPSRC 1/2/2010-31/1/2014.
  • “Quantum Multiplexer” EPSRC 1/1/2011-31/12/2013.
  • “Indirect Excitons Fundamental Physics and Applications – INDEX” EC FP7 initial training network 1/11/2011-31/10/2015.
  • “Quantum Cascade amplifiers for high power Terahertz time domain spectrometry” EPSRC 1/1/2012-31/12/2014.
  • “Spintronic device physics in Si/Ge Heterostructures” EPSRC 24/1/2012-23/7/2015.
  • “Mapping Spin Polarisation in Quasi-One-Dimensional Channels” EPSRC 1/5/2012-31/10/2013.
  • “Beyond Luttinger Liquids-spin-charge separation at high excitation energies” EPSRC 1/5/2012-31/10/2014.
  • “Quantum Cascade Lasers Based Terahertz Frequency COMB” European Union FP7-ICT 1/6/2012-31/5/2015.
  • “Beyond modulation doping” EPSRC 1/7/2012-30/6/2015.
  • “Developing thermodynamic probes to study two-dimensional electron systems” Leverhulme Trust 1/10/2012-30/9/2015
  • “Semiconductor Integrated Quantum Optical Circuits” EPSRC 16/1/2012-15/7/2017.
  • “Coherent Terahertz Systems (COTS)-opening up the terahertz spectrum for widespread application” EPSRC 1/5/2012-31/10/2017.
  • “Nanoelectronic Based Quantum Physics - Technology and Applications” EPSRC 1/10/2012-31/3/2018.
  • "Sound-Light Manipulation in the Terahertz (SOULMAN)" ERC 1/4/2014-31/3/2018.
  • "Fibre wavelength quantum relay (FQRelay)" InnovateUK  1/10/16-31/12/2017.
  • "Advanced Materials Characterisation Suite in the Maxwell Centre, University of Cambridge" EPSRC 1/5/2015-30/4/2019.
  • "Versatile Quantum Multiplexing" EPSRC 1/11/2015-31/10/2018.
  • "Practical realisation of the Ampere" EURAMET 1/5/2016-30/4/2019.
  • "Fibre Wavelength Quantum Networks (FQNet)" EPSRC/InnovateUK 1/10/2017-31/3/2019.

Current Research Grants:

  • "Semiconductor Quantum Photonics: Control of Spin, Exciton and Photon Interactions by Nano-Photonic Design" EPSRC 20/7/2016-19/7/2021.
  • “Multiplexed quantum circuits” EPSRC 1/3/2019-28/2/2022.
  • "HyperTerahertz - High precision terahertz spectroscopy and microscopy" EPSRC 1/6/2017-31/5/2022.
  • "Agile Quantum Safe Communications (AQUASEC)" Innovate UK 1/11/2018-31/03/2021.
  • "Non-Ergodic quantum manipulation" EPSRC 1/1/2019-31/12/2023.
  • "Single Photon Infrared Imaging, Detection and Ranging (SPIDAR)" Innovate UK, 1/10/2020 to 20/9/2023.
  • “UK National Foundry for Quantum Components (QFoundry)” Innovate UK, 1/9/2020-31/8/2023.


In total with over 100 institutions worldwide, including:

Toshiba Research Europe Ltd, Teraview Ltd, E2V Ltd, NPL.

Universities:  Bath, Dundee, Exeter, Leeds, Lancaster, Imperial College, University College London, Royal Holloway College, Oxford, Southampton, Sheffield, ETH Zurich, New South Wales, Paris, Pisa, Taiwan and Sungkyunkwan


As of October 2020:

Over 1200 journal publications (38 in Nature journals, 6 in Science, 68 in Physical Review Letters, 179 in Physical Review B, 200 in Applied Physics Letters, 58 in Journal of Physics Condensed Matter, 37 in Optics Express, 10 in Optics Letters)

Web of Science: 32,000 citations, h-index 77 

Google Scholar: 48,000 citations, h-index 96





Key publications: 

"A Josephson relation for fractionally charged anyons". Kapfer M; Roulleau P; Santin M; Farrer I; Ritchie DA; Glattli DC. Science 363(6429):846-849 22 Feb 2019.

Low-bias terahertz amplitude modulator based on split-ring resonators and graphene

Innocenti R. Degl, Jessop D. S., Shah Y. D., Sibik J., Zeitler J. A., Kidambi P. R., Hofmann S., Beere H. E. and Ritchie D. A.ACS Nano8, 2548–2554 (2014).

"An entangled-light-emitting diode", Salter C. L., Stevenson R. M., Farrer I., Nicoll C. A., Ritchie D. A. and Shields A. J., Nature, 465, 594–597 (2010).

"Anomalous Coulomb drag in electron-hole bilayers", Croxall A. F., Gupta K. Das, Nicoll C. A., Thangaraj M., Beere H. E., Farrer I., Ritchie D. A. and Pepper M., Phys. Rev. Lett., 101, 246801 (2008).

"Gigahertz quantized charge pumping", Blumenthal M. D., Kaestner B., Li L., Giblin S., Janssen T. J. B. M., Pepper M., Anderson D., Jones G. A. C. and Ritchie D. A., Nature Physics, 3, 343–347 (2007).

"A semiconductor source of triggered entangled photon pairs", Stevenson R. M., Young R. J., Atkinson P., Cooper K., Ritchie D. A., and Shields A. J., Nature, 439 (7073), 179–182 (2006).

"2.9 THz quantum cascade lasers operating up to 70K in continuous wave", Barbieri S., Alton J., Beere H. E., Fowler J., Linfield E. H. and Ritchie D. A., Appl. Phys. Lett., 85, 1674 – 1676 (2004).

"Terahertz semiconductor-heterostructure laser", Kohler R., Tredicucci A., Beltram F., Beere H. E., Linfield E. H., Davies A. G., Ritchie D. A., Iotti R. C. and Rossi F., Nature, 417, 156–159 (2002).

"Electrically driven single-photon source", Yuan Z., Kardynal B. E., Stevenson R. M., Shields A. J., Lobo C. J., Cooper K., Beattie N. S., Ritchie D. A. and Pepper M., Science, 295, 102–105 (2002).

"One dimensional transport and the quantisation of the ballistic resistance", Wharam D. A., Thornton T. J., Newbury R., Pepper M., Ahmed H., Frost J. E. F., Hasko D. G., Peacock D. C., Ritchie D. A. and Jones G. A. C., J. Phys. C, 21, L209 – 214 (1988). 


Other publications: 

 "Long-term transmission of entangled photons from a single quantum dot over deployed fiber". Xiang Z-HHuwer JStevenson RMSkiba-Szymanska JWard MBFarrer I, Ritchie DA, Shields AJ. Sci Rep 9(1):4111 11 Mar 2019.

"Zero-Magnetic Field Fractional Quantum States". Kumar S; Pepper M; Holmes SN; Montagu H; Gul Y; Ritchie DA; Farrer I . Phys Rev Lett 122(8):086803 01 Mar 2019.

"A Josephson relation for fractionally charged anyons". Kapfer M; Roulleau P; Santin M; Farrer I; Ritchie DA; Glattli DC. Science 363(6429):846-849 22 Feb 2019.

"Frequency-tunable continuous-wave random lasers at terahertz frequencies". Biasco SBeere HE, Ritchie DA, Li LDavies AGLinfield EHVitiello MS. Light Sci Appl 8:43 2019. 

"Systematic Study of Ferromagnetism in CrxSb2-xTe3 Topological Insulator Thin Films using Electrical and Optical Techniques".  Singh A, Kamboj VSLiu J, Llandro JDuffy LBSenanayak SP, Beere HE, Ionescu A, Ritchie DA, Hesjedal T. Sci Rep 8(1):17024 19 Nov 2018.

"LO-Phonon Emission Rate of Hot Electrons from an On-Demand Single-Electron Source in a GaAs/AlGaAs Heterostructure"Johnson NEmary CRyu SSim H-SSee PFletcher JDGriffiths JPJones GACFarrer IRitchie DA. Phys Rev Lett 121(13):137703 28 Sep 2018.

"Imaging the Zigzag Wigner Crystal in Confinement-Tunable Quantum Wires". Ho S-CChang H-JChang C-HLo S-TCreeth GKumar SFarrer IRitchie D, Griffiths JJones G. Phys Rev Lett 121(10):106801 07 Sep 2018.

"A quantum light-emitting diode for the standard telecom window around 1,550 nm".Müller TSkiba-Szymanska JKrysa ABHuwer JFelle MAnderson M, Stevenson RMHeffernan JRitchie DA, Shields AJ. Nat Commun 9(1):862 28 Feb 2018.

"Quantum Engineering of InAs/GaAs Quantum Dot Based Intermediate Band Solar Cells".  Beattie NSSee PZoppi GUshasree PMDuchamp MFarrer IRitchie DA, Tomić S. ACS Photonics 4(11):2745-2750 15 Nov 2017.

 "On-Chip Andreev Devices: Hard Superconducting Gap and Quantum Transport in Ballistic Nb-In0.75 Ga0.25 As-Quantum-Well-Nb Josephson Junctions". Delfanazari K, Puddy RKMa PYi TCao MGul YFarrer IRitchie DA, Joyce HJ, Kelly MJ. Adv Mater 29(37):Oct 2017.

 "Terahertz Nanoscopy of Plasmonic Resonances with a Quantum Cascade Laser".  Degl'Innocenti R, Wallis R, Wei B, Xiao L, Kindness S, Mitrofanov OBraeuninger-Weimer P, Hofmann S, Beere H, Ritchie D. ACS Photonics 4(9):2150-2157 20 Sep 2017.

 "External amplitude and frequency modulation of a terahertz quantum cascade laser using metamaterial/graphene devices". Kindness SJ, Jessop DSWei B, Wallis RKamboj VS, Xiao L, Ren YBraeuninger-Weimer P, Aria AI, Hofmann SSci Rep 7(1):7657 09 Aug 2017.

"Anisotropic Pauli Spin Blockade of Holes in a GaAs Double Quantum Dot". Wang DQKlochan OHung J-TCulcer DFarrer IRitchie DA, Hamilton AR. Nano Lett 16(12):7685-7689 14 Dec 2016. 

 "A semiconductor photon-sorter". Bennett AJLee JP, Ellis DJPFarrer I, Ritchie DA, Shields AJ. Nat Nanotechnol 11(10):857-860 Oct 2016.

"Cavity-enhanced coherent light scattering from a quantum dot". Bennett AJLee JP, Ellis DJPMeany T, Murray EFloether FFGriffths JPFarrer I, Ritchie DA, Shields AJ. Sci Adv 2(4):e1501256 Apr 2016.

 "Graphene based plasmonic terahertz amplitude modulator operating above 100 MHz". Jessop DSKindness SJ, Xiao L, Braeuninger-Weimer P, Lin HRen YRen CXHofmann S, Zeitler JA, Beere HE. Applied Physics Letters 108(17):25 Apr 2016.

"Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum Hall Edge States". Kataoka MJohnson NEmary CSee PGriffiths JPJones GACFarrer IRitchie DA, Pepper M, Janssen TJBM. Phys Rev Lett 116(12):126803 25 Mar 2016. 

"Ultra-low-power hybrid light-matter solitons". Walker PM; Tinkler L; Skryabin DV; Yulin A; Royall B; Farrer I; Ritchie DA; Skolnick MS; Krizhanovskii DN.  Nat Commun 6(1):8317  24 Sep 2015.

"Harvesting dissipated energy with a mesoscopic ratchet". Roche B; Roulleau P; Jullien T; Jompol Y; Farrer I; Ritchie DA; Glattli. Nat Commun 6(1):6738  01 Apr 2015.

"All-electric all-semiconductor spin field-effect transistors". Chuang P; Ho S-C; Smith LW; Sfigakis F; Pepper M; Chen C-H; Fan J-C; Griffiths JP; Farrer I; Beere HE.  Nat Nanotechnol 10(1):35-39 Jan 2015.

"Low-bias terahertz amplitude modulator based on split-ring resonators and graphene". Degl'Innocenti R; Jessop DS; Shah YD; Sibik J; Zeitler JA; Kidambi PR; Hofmann S; Beere HE; Ritchie DA. ACS Nano 8(3):2548-2554 25 Mar 2014.

"Coherent dynamics of a telecom-wavelength entangled photon source". Ward MB; Dean MC; Stevenson RM; Bennett AJ; Ellis DJP; Cooper K; Farrer I; Nicoll CA; Ritchie DA; Shields AJ. Nat Commun 5(1):3316 (2014).

Teaching and Supervisions


Part II Quantum Condensed Matter Physics 2020-2021

Research supervision: 

Research Fellows:

MBE: Harvey Beere, Lucy Goff, James Aldous, Chong Chen.

THz: Harvey Beere, Varun Kamboj, Huifang Zhang.

Low dimensional transport:  Chong Chen.

Research Students:                              

Yuqing Wu,  Matthew Anderson, Ziheng Xiang, Nikita Almond, Louise Wells, Ginny Shooter, Wladislaw Michailow, Rose Scowen.

Professor of Experimental Physics, University of Cambridge
Professor of Semiconductor Science and Technology, Swansea University
Fellow and Director of Studies in Physics at Robinson College, University of Cambridge
Professor David  Ritchie

Contact Details

Email address: 
01223 337331
Takes PhD students
Not available for consultancy