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Nonmagnetic fractional conductance in high mobility InAs quantum point contacts

I. Villar Rodriguez1,2,*, Y. Gul1,2, C. P. Dempsey3, J. T. Dong4, S. N. Holmes2, C. J. Palmstrøm3,4, and M. Pepper1,2

  • *Contact author: uceeivi@ucl.ac.uk
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Phys. Rev. B 112, 075404 – Published 4 August, 2025

DOI: https://doi.org/10.1103/45nh-cld6

Abstract

In this paper, we report the magnetoelectronic properties of high mobility InAs quantum point contacts grown on InP substrates. The InAs quantum well is embedded between In0.72Ga0.28As cladding layers and In0.81Al0.19As barrier layers, and is populated via self-accumulation. The one-dimensional (1D) conductance reaches a maximum value of 17 plateaus, quantized in units of 2e2/h, where e is the fundamental unit of charge and h is Planck's constant. The in-plane effective g factor was estimated to be −10.9±1.5 for subband N=1 and −10.8±1.6 for subband N=2. Furthermore, a study of the nonmagnetic fractional conductance states at 0.2 (e2/h) and 0.1 (e2/h) is provided. While their origin remains under discussion, evidence suggests that they arise from strong electron-electron interactions and momentum-conserving backscattering between electrons in two distinct channels within the 1D region. This phenomenon may also be interpreted as an entanglement between the two channel directions facilitated by momentum-conserving backscattering.

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References (54)

  1. D. A. Wharam, T. J. Thornton, R. Newbury, M. Pepper, H. Ahmed, J. E. F. Frost, D. G. Hasko, D. C. Peacock, D. A. Ritchie, and G. A. C. Jones, One-dimensional transport and the quantisation of the ballistic resistance, J. Phys. C: Solid State Phys. 21, L209 (1988).
  2. B. J. van Wees, H. van Houten, C. W. J. Beenakker, J. G. Williamson, L. P. Kouwenhoven, D. van der Marel, and C. T. Foxon, Quantized conductance of point contacts in a two-dimensional electron gas, Phys. Rev. Lett. 60, 848 (1988).
  3. N. K. Patel, J. T. Nicholls, L. Martin-Moreno, M. Pepper, J. E. F. Frost, D. A. Ritchie, and G. A. C. Jones, Evolution of half plateaus as a function of electric field in a ballistic quasi-one-dimensional constriction, Phys. Rev. B 44, 13549 (1991).
  4. L. P. Kouwenhoven, B. J. van Wees, C. J. P. M. Harmans, J. G. Williamson, H. van Houten, C. W. J. Beenakker, C. T. Foxon, and J. J. Harris, Nonlinear conductance of quantum point contacts, Phys. Rev. B 39, 8040 (1989).
  5. K. J. Thomas, J. T. Nicholls, M. Y. Simmons, M. Pepper, D. R. Mace, and D. A. Ritchie, Possible spin polarization in a one-dimensional electron gas, Phys. Rev. Lett. 77, 135 (1996).
  6. A. Kristensen, H. Bruus, A. E. Hansen, J. B. Jensen, P. E. Lindelof, C. J. Marckmann, J. Nygård, C. B. Sørensen, F. Beuscher, A. Forchel, and M. Michel, Bias and temperature dependence of the 0.7 conductance anomaly in quantum point contacts, Phys. Rev. B 62, 10950 (2000).
  7. S. M. Cronenwett, H. J. Lynch, D. Goldhaber-Gordon, L. P. Kouwenhoven, C. M. Marcus, K. Hirose, N. S. Wingreen, and V. Umansky, Low-temperature fate of the 0.7 structure in a point contact: A Kondo-like correlated state in an open system, Phys. Rev. Lett. 88, 226805 (2002).
  8. M. J. Iqbal, R. Levy, E. J. Koop, J. B. Dekker, J. P. de Jong, J. H. M. van der Velde, D. Reuter, A. D. Wieck, R. Aguado, Y. Meir, and C. H. van der Wal, Odd and even Kondo effects from emergent localization in quantum point contacts, Nature (London) 501, 79 (2013).
  9. F. Bauer, J. Heyder, E. Schubert, D. Borowsky, D. Taubert, B. Bruognolo, D. Schuh, W. Wegscheider, J. von Delft, and S. Ludwig, Microscopic origin of the ‘0.7-anomaly’ in quantum point contacts, Nature (London) 501, 73 (2013).
  10. W. K. Hew, K. J. Thomas, M. Pepper, I. Farrer, D. Anderson, G. A. C. Jones, and D. A. Ritchie, Incipient formation of an electron lattice in a weakly confined quantum wire, Phys. Rev. Lett. 102, 056804 (2009).
  11. L. W. Smith, W. K. Hew, K. J. Thomas, M. Pepper, I. Farrer, D. Anderson, G. A. C. Jones, and D. A. Ritchie, Row coupling in an interacting quasi-one-dimensional quantum wire investigated using transport measurements, Phys. Rev. B 80, 041306(R) (2009).
  12. S. Kumar, K. J. Thomas, L. W. Smith, M. Pepper, G. L. Creeth, I. Farrer, D. Ritchie, G. Jones, and J. Griffiths, Many-body effects in a quasi-one-dimensional electron gas, Phys. Rev. B 90, 201304(R) (2014).
  13. J. S. Meyer and K. A. Matveev, Wigner crystal physics in quantum wires, J. Phys.: Condens. Matter 21, 023203 (2009).
  14. S.-T. Lo, C.-H. Chen, J.-C. Fan, L. W. Smith, G. L. Creeth, C.-W. Chang, M. Pepper, J. P. Griffiths, I. Farrer, H. E. Beere, G. A. C. Jones, D. A. Ritchie, and T.-M. Chen, Controlled spatial separation of spins and coherent dynamics in spin-orbit-coupled nanostructures, Nat. Commun. 8, 15997 (2017).
  15. T.-M. Chen, M. Pepper, I. Farrer, G. A. C. Jones, and D. A. Ritchie, All-electrical injection and detection of a spin-polarized current using 1D conductors, Phys. Rev. Lett. 109, 177202 (2012).
  16. P. Debray, S. M. S. Rahman, R. S. N. J. Wan, M. Cahay, A. T. Ngo, S. E. Ulloa, S. T. Herbert, M. Muhammad, and M. Johnson, All-electric quantum point contact spin-polarizer, Nat. Nanotechnol. 4, 759 (2009).
  17. P. Chuang, S.-C. Ho, L. W. Smith, F. Sfigakis, M. Pepper, C.-H. Chen, J.-C. Fan, J. P. Griffiths, I. Farrer, H. E. Beere, G. A. C. Jones, D. A. Ritchie, and T.-M. Chen, All-electric all-semiconductor spin field-effect transistors, Nat. Nanotechnol. 10, 35 (2015).
  18. T. Tschirky, S. Mueller, C. A. Lehner, S. Fält, T. Ihn, K. Ensslin, and W. Wegscheider, Scattering mechanisms of highest-mobility InAs/AlxGa1−xSb quantum wells, Phys. Rev. B 95, 115304 (2017).
  19. C. Thomas, A. T. Hatke, A. Tuaz, R. Kallaher, T. Wu, T. Wang, R. E. Diaz, G. C. Gardner, M. A. Capano, and M. J. Manfra, High-mobility InAs 2DEGs on GaSb substrates: A platform for mesoscopic quantum transport, Phys. Rev. Mater. 2, 104602 (2018).
  20. J. Shabani, A. P. McFadden, B. Shojaei, and C. J. Palmstrøm, Gating of high-mobility InAs metamorphic heterostructures, Appl. Phys. Lett. 105, 262105 (2014).
  21. A. T. Hatke, T. Wang, C. Thomas, G. C. Gardner, and M. J. Manfra, Mobility in excess of 106cm2/Vs in InAs quantum wells grown on lattice mismatched InP substrates, Appl. Phys. Lett. 111, 142106 (2017).
  22. S. Mueller, C. Mittag, T. Tschirky, C. Charpentier, W. Wegscheider, K. Ensslin, and T. Ihn, Edge transport in InAs and InAs/GaSb quantum wells, Phys. Rev. B 96, 075406 (2017).
  23. C. P. Dempsey, J. T. Dong, I. Villar Rodriguez, Y. Gul, S. Chatterjee, M. Pendharkar, S. N. Holmes, M. Pepper, and C. J. Palmstrøm, Effects of strain compensation on electron mobilities in InAs quantum wells grown on InP(001), Phys. Rev. Mater. 9, 054607 (2025).
  24. A. Benali, P. Rajak, R. Ciancio, J. Plaisier, S. Heun, and G. Biasiol, Metamorphic InAs/InGaAs QWs with electron mobilities exceeding 7×105cm2/V s, J. Cryst. Growth 593, 126768 (2022).
  25. J. Shabani, S. Das Sarma, and C. J. Palmstrøm, An apparent metal-insulator transition in high-mobility two-dimensional InAs heterostructures, Phys. Rev. B 90, 161303(R) (2014).
  26. C. R. Pidgeon, D. L. Mitchell, and R. N. Brown, Interband magnetoabsorption in InAs and InSb, Phys. Rev. 154, 737 (1967).
  27. W. Desrat, F. Giazotto, V. Pellegrini, F. Beltram, F. Capotondi, G. Biasiol, L. Sorba, and D. K. Maude, Magnetotransport in high-g-factor low-density two-dimensional electron systems confined in In0.75Ga0.25As/In0.75Al0.25As quantum wells, Phys. Rev. B 69, 245324 (2004).
  28. M. J. Snelling, G. P. Flinn, A. S. Plaut, R. T. Harley, A. C. Tropper, R. Eccleston, and C. C. Phillips, Magnetic g factor of electrons in GaAs/AlxGa1−xAs quantum wells, Phys. Rev. B 44, 11345 (1991).
  29. A. Das, Y. Ronen, Y. Most, Y. Oreg, M. Heiblum, and H. Shtrikman, Zero-bias peaks and splitting in an Al-InAs nanowire topological superconductor as a signature of Majorana fermions, Nat. Phys. 8, 887 (2012).
  30. R. M. Lutchyn, J. D. Sau, and S. Das Sarma, Majorana fermions and a topological phase transition in semiconductor-superconductor heterostructures, Phys. Rev. Lett. 105, 077001 (2010).
  31. Y. Oreg, G. Refael, and F. von Oppen, Helical liquids and Majorana bound states in quantum wires, Phys. Rev. Lett. 105, 177002 (2010).
  32. Microsoft Azure Quantum, Interferometric single-shot parity measurement in InAs-Al hybrid devices, Nature (London) 638, 651 (2025).
  33. S. Sarma, M. Freedman, and C. Nayak, Majorana zero modes and topological quantum computation, npj Quantum Inf. 1, 15001 (2015).
  34. S. Matsuo, H. Kamata, S. Baba, R. S. Deacon, J. Shabani, C. J. Palmstrøm, and S. Tarucha, Magnetic field inducing Zeeman splitting and anomalous conductance reduction of half-integer quantized plateaus in InAs quantum wires, Phys. Rev. B 96, 201404(R) (2017).
  35. C. Mittag, M. Karalic, Z. Lei, C. Thomas, A. Tuaz, A. T. Hatke, G. C. Gardner, M. J. Manfra, T. Ihn, and K. Ensslin, Gate-defined quantum point contact in an InAs two-dimensional electron gas, Phys. Rev. B 100, 075422 (2019).
  36. J. S. Lee, B. Shojaei, M. Pendharkar, A. P. McFadden, Y. Kim, H. J. Suominen, M. Kjaergaard, F. Nichele, H. Zhang, C. M. Marcus, and C. J. Palmstrøm, Transport studies of epi-Al/InAs two-dimensional electron gas systems for required building-blocks in topological superconductor networks, Nano Lett. 19, 3083 (2019).
  37. C. L. Hsueh, P. Sriram, T. Wang, C. Thomas, G. Gardner, M. A. Kastner, M. J. Manfra, and D. Goldhaber-Gordon, Clean quantum point contacts in an InAs quantum well grown on a lattice-mismatched InP substrate, Phys. Rev. B 105, 195303 (2022).
  38. Y. Gul, S. N. Holmes, M. Myronov, S. Kumar, and M. Pepper, Self-organised fractional quantisation in a hole quantum wire, J. Phys.: Condens. Matter 30, 09LT01 (2018).
  39. L. Liu, Y. Gul, S. N. Holmes, C. Chen, I. Farrer, D. A. Ritchie, and M. Pepper, Possible zero-magnetic field fractional quantization in In0.75Ga0.25As heterostructures, Appl. Phys. Lett. 123, 183502 (2023).
  40. S. Kumar, M. Pepper, S. N. Holmes, H. Montagu, Y. Gul, D. A. Ritchie, and I. Farrer, Zero-magnetic field fractional quantum states, Phys. Rev. Lett. 122, 086803 (2019).
  41. C. Ford, CryoMeas — A Data-Acquisition Program for LabView (The University of Cambridge, Cambridge, 2023).
  42. F. Capotondi, G. Biasiol, I. Vobornik, L. Sorba, F. Giazotto, A. Cavallini, and B. Fraboni, Two-dimensional electron gas formation in undoped In0.75Ga0.25As/In0.75Al0.25As quantum wells, J. Vac. Sci. Technol. B 22, 702 (2004).
  43. P. N. Brounkov, T. Benyattou, G. Guillot, and S. A. Clark, Admittance spectroscopy of InAlAs/InGaAs single-quantum-well structure with high concentration of electron traps in InAlAs layers, J. Appl. Phys. 77, 240 (1995).
  44. S. P. Le and T.-K. Suzuki, Electron mobility anisotropy in InAs/GaAs(001) heterostructures, Appl. Phys. Lett. 118, 182101 (2021).
  45. M. Prager, M. Trottmann, J. Schmidt, L. Ebnet, D. Schuh, and D. Bougeard, Gating of two-dimensional electron systems in (In,Ga)As/(In,Al)As heterostructures: The role of intrinsic (In,Al)As deep donor defects, Phys. Rev. Appl. 16, 064028 (2021).
  46. Y. Gul, G. L. Creeth, D. English, S. N. Holmes, K. J. Thomas, I. Farrer, D. J. Ellis, D. A. Ritchie, and M. Pepper, Conductance quantisation in patterned gate In0.75Ga0.25As structures up to 6×(2e2/h), J. Phys.: Condens. Matter 31, 104002 (2019).
  47. T.-M. Chen, A. C. Graham, M. Pepper, I. Farrer, and D. A. Ritchie, Bias-controlled spin polarization in quantum wires, Appl. Phys. Lett. 93, 032102 (2008).
  48. G. Shavit and Y. Oreg, Fractional conductance in strongly interacting 1D systems, Phys. Rev. Lett. 123, 036803 (2019).
  49. F. Capotondi, G. Biasiol, D. Ercolani, and L. Sorba, Scattering mechanisms in undoped In0.75Ga0.25As/In0.75Al0.25As two-dimensional electron gases, J. Cryst. Growth 278, 538 (2005).
  50. L. Saminadayar, D. C. Glattli, Y. Jin, and B. Etienne, Observation of the e/3 fractionally charged Laughlin quasiparticle, Phys. Rev. Lett. 79, 2526 (1997).
  51. A. Bid, N. Ofek, M. Heiblum, V. Umansky, and D. Mahalu, Shot noise and charge at the 2/3 composite fractional quantum Hall state, Phys. Rev. Lett. 103, 236802 (2009).
  52. R. de Picciotto, M. Reznikov, M. Heiblum, V. Umansky, G. Bunin, and D. Mahalu, Direct observation of a fractional charge, Nature (London) 389, 162 (1997).
  53. M. Reznikov, R. de Picciotto, T. Griffiths, M. Heiblum, and V. Umansky, Observation of quasiparticles with one-fifth of an electron's charge, Nature (London) 399, 238 (1999).
  54. M. Dolev, M. Heiblum, V. Umansky, A. Stern, and D. Mahalu, Observation of a quarter of an electron charge at the ν=5/2 quantum Hall state, Nature (London) 452, 829 (2008).

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Phys. Rev. B 112, 075404– Published 4 August, 2025
  • Received 28 February 2025
  • Revised 24 June 2025
  • Accepted 8 July 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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