12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Gigahertz quantized charge pumping in graphene ...
View graph of relations

Text available via DOI:

« Back

Gigahertz quantized charge pumping in graphene quantum dots

Research output: Contribution to journalJournal article

Published

  • M. R. Connolly
  • K. L. Chiu
  • S. P. Giblin
  • M. Kataoka
  • J. D. Fletcher
  • C. Chua
  • J. P. Griffiths
  • G. A. C. Jones
  • Vladimir Falko
  • C. G. Smith
  • T. J. B. M. Janssen
Journal publication date06/2013
JournalNature Nanotechnology
Journal number6
Volume8
Number of pages4
Pages417-420
Original languageEnglish

Abstract

Single-electron pumps are set to revolutionize electrical metrology by enabling the ampere to be redefined in terms of the elementary charge of an electron(1). Pumps based on lithographically fixed tunnel barriers in mesoscopic metallic systems(2) and normal/superconducting hybrid turnstiles(3) can reach very small error rates, but only at megahertz pumping speeds that correspond to small currents of the order of picoamperes. Tunable barrier pumps in semiconductor structures are operated at gigahertz frequencies(1,4), but the theoretical treatment of the error rate is more complex and only approximate predictions are available(5). Here, we present a monolithic, fixed-barrier single-electron pump made entirely from graphene that performs at frequencies up to several gigahertz. Combined with the record-high accuracy of the quantum Hall effect(6) and proximity-induced Josephson junctions(7), quantized- current generation brings an all-graphene closure of the quantum metrological triangle within reach(8,9). Envisaged applications for graphene charge pumps outside quantum metrology include single-photon generation via electron-hole recombination in electrostatically doped bilayer graphene reservoirs(10), single Dirac fermion emission in relativistic electron quantum optics(11) and read-out of spin-based graphene qubits in quantum information processing(12).