Abstract
Spin qubits have been successfully realized in electrostatically defined, lateral few-electron quantum-dot circuits1,2,3,4. Qubit readout typically involves spin to charge information conversion, followed by a charge measurement made using a nearby biased quantum point contact1,5,6 (QPC). It is critical to understand the back-action disturbances resulting from such a measurement approach7,8. Previous studies have indicated that QPC detectors emit phonons which are then absorbed by nearby qubits9,10,11,12,13. We report here the observation of a pronounced back-action effect in multiple dot circuits, where the absorption of detector-generated phonons is strongly modified by a quantum interference effect, and show that the phenomenon is well described by a theory incorporating both the QPC and coherent phonon absorption. Our combined experimental and theoretical results suggest strategies to suppress back-action during the qubit readout procedure.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Hanson, R., Kouwenhoven, L. P., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spins in few-electron quantum dots. Rev. Mod. Phys. 79, 1217–1265 (2007).
Fujisawa, T., Hayashi, T. & Sasaki, S. Time-dependent single-electron transport through quantum dots. Rep. Prog. Phys. 69, 759–796 (2006).
Petersson, K. D., Petta, J. R., Lu, H. & Gossard, A. C. Quantum coherence in a one-electron semiconductor charge qubit. Phys. Rev. Lett. 105, 246804 (2010).
Gaudreau, L. et al. Coherent control of three-spin states in a triple quantum dot. Nature Phys. 8, 54–58 (2011).
Field, M. et al. Coulomb blockade as a noninvasive probe of local density of states. Phys. Rev. Lett. 77, 350–353 (1996).
Elzerman, J. M. et al. Few-electron quantum dot circuit with integrated charge read out. Phys. Rev. B 67, 161308 (2003).
Aguado, R. & Kouwenhoven, L. P. Double quantum dots as detectors of high-frequency quantum noise in mesoscopic conductors. Phys. Rev. Lett. 84, 1986–1989 (2000).
Young, C. E. & Clerk, A. A. Inelastic back-action due to quantum point contact charge fluctuations. Phys. Rev. Lett. 104, 186803 (2010).
Khrapai, V. S., Ludwig, S., Kotthaus, J. P., Tranitz, H. P. & Wegscheider, W. Double-dot quantum ratchet driven by an independently biased quantum point contact. Phys. Rev. Lett. 97, 176803 (2006).
Taubert, D. et al. Telegraph noise in coupled quantum dot circuits induced by a quantum point contact. Phys. Rev. Lett. 100, 176805 (2008).
Gasser, U. et al. Statistical electron excitation in a double quantum dot induced by two independent quantum point contacts. Phys. Rev. B 79, 035303 (2009).
Schinner, G. J., Tranitz, H. P., Wegscheider, W., Kotthaus, J. P. & Ludwig, S. Phonon-mediated nonequilibrium interaction between nanoscale devices. Phys. Rev. Lett. 102, 186801 (2009).
Harbusch, D., Taubert, D., Tranitz, H. P., Wegscheider, W. & Ludwig, S. Phonon-mediated versus coulombic back-action in quantum dot circuits. Phys. Rev. Lett. 104, 196801 (2010).
Miller, A. & Abrahams, E. Impurity conduction at low concentrations. Phys. Rev. 120, 745–755 (1960).
Imry, Y. in Tunnelling Phenomena in Solids (eds Burstein, E. & Lundqvsit, S.) 563–576 (Plenum, 1969).
Brandes, T. Coherent and collective quantum optical effects in mesoscopic systems. Phys. Rep. 408, 315–474 (2005).
Fujisawa, T. et al. Spontaneous emission spectrum in double quantum dot devices. Science 282, 932–935 (1998).
Roulleau, P. et al. Coherent electron–phonon coupling in tailored quantum systems. Nature Commun. 2, 239 (2011).
Gaudreau, L. et al. Stability diagram of a few-electron triple dot. Phys. Rev. Lett. 97, 036807 (2006).
Schröer, D. et al. Electrostatically defined serial triple quantum dot charged with few electrons. Phys. Rev. B 76, 075306 (2007).
Rogge, M. C. & Haug, R. J. Two-path transport measurements on a triple quantum dot. Phys. Rev. B 77, 193306 (2008).
Rogge, M. C. & Haug, R. J. The three dimensionality of triple quantum dot stability diagrams. New J. Phys. 11, 113037 (2009).
Granger, G. et al. Three-dimensional transport diagram of a triple quantum dot. Phys. Rev. B 82, 075304 (2010).
Jasiukiewicz, C. Acoustic phonon emission by hot 2D electrons: The angular distribution of the emitted phonon power. Semicond. Sci. Technol. 13, 537–547 (1998).
Taubert, D., Schuh, D., Wegscheider, W. & Ludwig, S. Determination of energy scales in few-electron double quantum dots. Rev. Scient. Inst. 82, 123905 (2011).
Pedersen, M., van Langen, S. & Büttiker, M. Charge fluctuations in quantum point contacts and chaotic cavities in the presence of transport. Phys. Rev. B 57, 1838–1846 (1998).
Acknowledgements
S.L. and D. T. acknowledge financial support by the German Science Foundation via SFB 631, LU 819/4-1, and the German Excellence Initiative via the ‘Nanosystems Initiative Munich’ (NIM). G.G. acknowledges funding from the NRC–CNRS collaboration. A.S.S. and A.A.C. acknowledge funding from NSERC and CIFAR.
Author information
Authors and Affiliations
Contributions
D.T. fabricated the DQD samples, performed the DQD experiments and analysed the data. D.H. performed preliminary experiments on another DQD sample. A.K. fabricated the TQD sample. L.G., G.G. and S.S. performed the TQD experiments and analysed the data. P.Z. assisted in these experiments. D.S. and W.W. grew the heterostructures for the DQD samples; Z.R.W. optimized and grew the heterostructure for the TQD sample. D.T., L.G., C.E.Y., A.A.C., A.S.S. and S.L. wrote the paper. C.E.Y. and A.A.C. developed the theoretical model and supported both experimental groups. A.S.S. and S.L. supervised the experimental collaboration from Ottawa and Munich. The experiments have been supervised collaboratively by A.S.S. and S.L.; the theoretical modelling was surpervised by A.A.C.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 652 kb)
Rights and permissions
About this article
Cite this article
Granger, G., Taubert, D., Young, C. et al. Quantum interference and phonon-mediated back-action in lateral quantum-dot circuits. Nature Phys 8, 522–527 (2012). https://doi.org/10.1038/nphys2326
Received:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/nphys2326
This article is cited by
-
Hyperfine-phonon spin relaxation in a single-electron GaAs quantum dot
Nature Communications (2018)
-
Engineering the quantum-classical interface of solid-state qubits
npj Quantum Information (2015)
-
Formation of a protected sub-band for conduction in quantum point contacts under extreme biasing
Nature Nanotechnology (2014)
-
Quantum strain sensor with a topological insulator HgTe quantum dot
Scientific Reports (2014)
-
Raman phonon emission in a driven double quantum dot
Nature Communications (2014)
