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  • Letter
  • Open Access

Cavity-assisted spin selection in one-dimensional conductors

Vivek Kumar1, Joshua Coop1, Yingshi Duo1, Ian Farrer2, David A. Ritchie3, and Sanjeev Kumar1,*

  • *Contact author: sanjeev.kumar@ucl.ac.uk
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Phys. Rev. B 114, L051402 – Published 7 July, 2026

DOI: https://doi.org/10.1103/b542-3g2c

Abstract

Spontaneous spin polarization in quasi-one-dimensional (1D) electron systems is inherently fragile, often masked by structural disorder or potential anharmonicity. Here we report the deterministic stabilization of an exchange-driven spin gap, manifesting as a robust 0.5(2e2/h) conductance plateau at zero magnetic field in a mesoscopic bilayer cavity. We demonstrate that this many-body phase is governed by a dual-parity protection mechanism. The spectral isolation of the tunnel-coupled bilayer energetically protects the ground state, while the symmetric harmonicity of the lateral cavity geometry shields the 1D van Hove singularity against transverse mode mixing. Breaking this spatial parity via asymmetric gating or localized central-gate screening violates the Stoner criterion for 1D ferromagnetism, quenching the 0.5(2e2/h) state and restoring spin-degenerate transport. Our findings establish electrostatic spatial parity as a macroscopic, tunable lever for engineering correlated quantum phases in mesoscopic architectures.

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References (66)

  1. 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).
  2. 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 21, L209 (1988).
  3. 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).
  4. S. Kumar, M. Pepper, D. Ritchie, I. Farrer, and H. Montagu, Formation of a non-magnetic, odd-denominator fractional quantized conductance in a quasi-one-dimensional electron system, Appl. Phys. Lett. 115, 123104 (2019).
  5. 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).
  6. V. Kumar, Y. Duo, P. See, J. P. Griffiths, D. A. Ritchie, I. Farrer, and S. Kumar, Correlation effects mediated by disorders in one-dimensional channels, Phys. Rev. B 112, 035404 (2025).
  7. A. G. Pogosov, A. A. Shevyrin, D. A. Pokhabov, E. Yu Zhdanov, and S. Kumar, Suspended semiconductor nanostructures: Physics and technology, J. Phys.: Condens. Matter 34, 263001 (2022).
  8. K. J. Thomas, J. T. Nicholls, N. J. Appleyard, M. Y. Simmons, M. Pepper, D. R. Mace, W. R. Tribe, and D. A. Ritchie, Interaction effects in a one-dimensional constriction, Phys. Rev. B 58, 4846 (1998).
  9. T. Rejec and Y. Meir, Magnetic impurity formation in quantum point contacts, Nature (London) 442, 900 (2006).
  10. K.-F. Berggren and M. Pepper, Electrons in one dimension, Philos. Trans. R. Soc. A 368, 1141 (2010).
  11. S. Kumar and M. Pepper, Interactions and non-magnetic fractional quantization in one-dimension, Appl. Phys. Lett. 119, 110502 (2021).
  12. R. Crook, J. Prance, K. J. Thomas, S. J. Chorley, I. Farrer, D. A. Ritchie, M. Pepper, and C. G. Smith, Conductance quantization at a half-integer plateau in a symmetric GaAs quantum wire, Science 312, 1359 (2006).
  13. P. Debray, S. M. S. Rahman, J. Wan, R. S. Newrock, 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).
  14. 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 et al., All-electric all-semiconductor spin field-effect transistors, Nat. Nanotechnol. 10, 35 (2015).
  15. R. Davies, I. V. Lerner, and I. V. Yurkevich, Resonant fractional conductance through a 1D Wigner chain, Commun. Phys. 7, 67 (2024).
  16. D. J. Reilly, T. M. Buehler, J. L. O'Brien, A. R. Hamilton, A. S. Dzurak, R. G. Clark, B. E. Kane, L. N. Pfeiffer, and K. W. West, Density-dependent spin polarization in ultra-low-disorder quantum wires, Phys. Rev. Lett. 89, 246801 (2002).
  17. 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).
  18. Y. Duo, J. Coop, I. Farrer, D. A. Ritchie, and S. Kumar, Magnetoelectric subbands in the one-dimensional to quasi-one-dimensional confined regime, Phys. Rev. B 113, 245304 (2026).
  19. E. C. Stoner, Collective electron ferromagnetism, Proc. R. Soc. Lond. A 165, 372 (1938).
  20. C.-K. Wang and K.-F. Berggren, Spin splitting of subbands in quasi-one-dimensional electron quantum channels, Phys. Rev. B 54, R14257(R) (1996).
  21. K.-F. Berggren and I. I. Yakimenko, Effects of exchange and electron correlation on conductance and nanomagnetism in ballistic semiconductor quantum point contacts, Phys. Rev. B 66, 085323 (2002).
  22. S. H. Abedinpour, M. Polini, A. H. MacDonald, B. Tanatar, M. P. Tosi, and G. Vignale, Theory of the pseudospin resonance in semiconductor bilayers, Phys. Rev. Lett. 99, 206802 (2007).
  23. J. P. Eisenstein, Exciton condensation in bilayer quantum Hall systems, Annu. Rev. Condens. Matter Phys. 5, 159 (2014).
  24. J. Shabani, T. Gokmen, Y. T. Chiu, and M. Shayegan, Evidence for developing fractional quantum Hall states at even denominator 1/2 and 1/4 fillings in asymmetric wide quantum wells, Phys. Rev. Lett. 103, 256802 (2009).
  25. J. T. Nicholls, N. P. R. Hill, B. Kardynal, N. Turner, E. H. Linfield, D. A. Ritchie, C. H. W. Barnes, G. A. C. Jones, and M. Pepper, The investigation of 1D and 2D phenomena using double-layer electron systems, Physica E 3, 52 (1998).
  26. A. F. Croxall, K. Das Gupta, C. A. Nicoll, H. E. Beere, I. Farrer, D. A. Ritchie, and M. Pepper, Possible effect of collective modes in zero magnetic field transport in an electron-hole bilayer, Phys. Rev. B 80, 125323 (2009).
  27. A. Siddiki, Self-consistent Coulomb picture of an electron-electron bilayer system, Phys. Rev. B 75, 155311 (2007).
  28. S. Faniel, E. Tutuc, E. P. De Poortere, C. Gustin, A. Vlad, S. Melinte, M. Shayegan, and V. Bayot, Thermopower of interacting GaAs bilayer hole systems in the reentrant insulating phase near ν=1, Phys. Rev. Lett. 94, 046802 (2005).
  29. Y. Zhang, J. K. Jain, and J. P. Eisenstein, Tunnel transport and interlayer excitons in bilayer fractional quantum Hall systems, Phys. Rev. B 95, 195105 (2017).
  30. C. Wang, A. Gupta, S. K. Singh, Y. J. Chung, L. N. Pfeiffer, K. W. West, K. W. Baldwin, R. Winkler, and M. Shayegan, Even-denominator fractional quantum Hall state at filling factor ν=3/4, Phys. Rev. Lett. 129, 156801 (2022).
  31. K. J. Thomas, J. T. Nicholls, M. Y. Simmons, W. R. Tribe, A. G. Davies, and M. Pepper, Controlled wave-function mixing in strongly coupled one-dimensional wires, Phys. Rev. B 59, 12252 (1999).
  32. K. J. Thomas, J. T. Nicholls, W. R. Tribe, M. Y. Simmons, A. G. Davies, D. A. Ritchie, and M. Pepper, Bonding and antibonding states in strongly coupled ballistic one-dimensional wires, Physica E 6, 581 (2000).
  33. S. Ichinokura, T. Hatano, W. Izumida, K. Nagase, and Y. Hirayama, Electrical control of tunnel coupling between vertically coupled quantum point contacts, Appl. Phys. Lett. 103, 062106 (2013).
  34. S. F. Fischer, G. Apetrii, U. Kunze, D. Schuh, and G. Abstreiter, Magnetotransport spectroscopy of spatially coincident coupled electron waveguides, Phys. Rev. B 71, 195330 (2005).
  35. S. F. Fischer, G. Apetrii, U. Kunze, D. Schuh, and G. Abstreiter, Tunnel-coupled one-dimensional electron systems with large subband separations, Phys. Rev. B 74, 115324 (2006).
  36. Y. Jompol, C. J. B. Ford, I. Farrer, G. A. C. Jones, D. Anderson, D. A. Ritchie, T. W. Silk, and A. J. Schofield, Probing e–e interactions in a periodic array of GaAs quantum wires, Physica E 40, 1220 (2008).
  37. Y. Jompol, C. J. B. Ford, J. P. Griffiths, I. Farrer, G. A. C. Jones, D. Anderson, D. A. Ritchie, T. W. Silk, and A. J. Schofield, Probing spin-charge separation in a Tomonaga-Luttinger liquid, Science 325, 597 (2009).
  38. K. L. Hudson, A. Srinivasan, O. Goulko, J. Adam, Q. Wang, L. A. Yeoh, O. Klochan, I. Farrer, D. A. Ritchie, A. Ludwig, et al., New signatures of the spin gap in quantum point contacts, Nat. Commun. 12, 5 (2021).
  39. 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).
  40. L. W. Smith, A. R. Hamilton, K. J. Thomas, M. Pepper, I. Farrer, J. P. Griffiths, G. A. C. Jones, and D. A. Ritchie, Compressibility measurements of quasi-one-dimensional quantum wires, Phys. Rev. Lett. 107, 126801 (2011).
  41. E. Tutuc, E. P. De Poortere, S. J. Papadakis, and M. Shayegan, In-plane magnetic field-induced spin polarization and transition to insulating behavior in two-dimensional hole systems, Phys. Rev. Lett. 86, 2858 (2001).
  42. O. M. Auslaender, H. Steinberg, A. Yacoby, Y. Tserkovnyak, B. I. Halperin, K. W. Baldwin, L. N. Pfeiffer, and K. W. West, Spin-charge separation and localization in one dimension, Science 308, 88 (2005).
  43. G. Gumbs, Tunneling of two interacting electrons in a quantum wire, Solid State Commun. 128, 443 (2003).
  44. C. Yan, S. Kumar, M. Pepper, P. See, I. Farrer, D. Ritchie, J. Griffiths, and G. Jones, Interference effects in a tunable quantum point contact integrated with an electronic cavity, Phys. Rev. Appl. 8, 024009 (2017).
  45. A. A. Kozikov, D. Weinmann, C. Rössler, T. Ihn, K. Ensslin, C. Reichl, and W. Wegscheider, Electron backscattering in a cavity: Ballistic and coherent effects, Phys. Rev. B 94, 195428 (2016).
  46. S. E. Ulloa, E. Castaño, and G. Kirczenow, Ballistic transport in a novel one-dimensional superlattice, Phys. Rev. B 41, 12350 (1990).
  47. J. H. Davies, I. A. Larkin, and E. V. Sukhorukov, Modeling the patterned two-dimensional electron gas: Electrostatics, J. Appl. Phys. 77, 4504 (1995).
  48. S.-q. Yuan and B.-y. Gu, Effect of geometry-induced scattering on the quantum conductance in double-quantum-point constrictions connected in series by a cavity, J. Appl. Phys. 73, 7496 (1993).
  49. Y. Takagaki, M. ElHassan, A. Shailos, C. Prasad, J. P. Bird, D. K. Ferry, K. H. Ploog, L.-H. Lin, N. Aoki, and Y. Ochiai, Magnetic-field-controlled electron dynamics in quantum cavities, Phys. Rev. B 62, 10255 (2000).
  50. D. A. Wharam, M. Pepper, H. Ahmed, J. E. F. Frost, D. G. Hasko, D. C. Peacock, D. A. Ritchie, and G. A. C. Jones, Addition of the one-dimensional quantised ballistic resistance, J. Phys. C 21, L887 (1988).
  51. C. W. J. Beenakker and H. van Houten, Magnetotransport and nonadditivity of point-contact resistances in series, Phys. Rev. B 39, 10445(R) (1989).
  52. L. Van Hove, The occurrence of singularities in the elastic frequency distribution of a crystal, Phys. Rev. 89, 1189 (1953).
  53. J. S. Meyer and K. A. Matveev, Wigner crystal physics in quantum wires, J. Phys.: Condens. Matter 21, 023203 (2009).
  54. A. Chaplik, Instability of quasi-one-dimensional electron chain and the “string-zigzag” structural transition, Pis'ma Zh. Eksp. Teor. Fiz. 31, 275 (1980) [JETP Lett. 31, 252 (1980)].
  55. H. Montagu, I. Farrer, D. Ritchie, and S. Kumar, Spin polarised quantum conductance in 1D channels, Appl. Phys. Express 18, 015002 (2025).
  56. W. E. Liu, S. Chesi, D. Webb, U. Zülicke, R. Winkler, R. Joynt, and D. Culcer, Generalized Stoner criterion and versatile spin ordering in two-dimensional spin-orbit coupled electron systems, Phys. Rev. B 96, 235425 (2017).
  57. S. Liu, C. Wang, B. Wang, Y. Jia, and J. Cho, Flat-band ferromagnetism in the quasi-one-dimensional electride Y2Cl3 induced by hole doping, Phys. Rev. B 110, 024413 (2024).
  58. T. Cao, Z. Li, and S. G. Louie, Tunable magnetism and half-metallicity in hole-doped monolayer GaSe, Phys. Rev. Lett. 114, 236602 (2015).
  59. N. D. Mermin and H. Wagner, Absence of ferromagnetism or antiferromagnetism in one-or two-dimensional isotropic Heisenberg models, Phys. Rev. Lett. 17, 1133 (1966).
  60. K.-F. Berggren, T. J. Thornton, D. J. Newson, and M. Pepper, Magnetic depopulation of 1D subbands in a narrow 2D electron gas in a GaAs:AlGaAs heterojunction, Phys. Rev. Lett. 57, 1769 (1986).
  61. L. P. Kouwenhoven, B. J. van Wees, W. Kool, C. J. P. M. Harmans, A. A. M. Staring, and C. T. Foxon, Transition from Ohmic to adiabatic transport in quantum point contacts in series, Phys. Rev. B 40, 8083(R) (1989).
  62. P. L. McEuen, B. W. Alphenaar, R. G. Wheeler, and R. N. Sacks, Resonant transport effects due to an impurity in a narrow constriction, Surf. Sci. 229, 312 (1990).
  63. D. Terasawa, S. Norimoto, T. Arakawa, M. Ferrier, A. Fukuda, K. Kobayashi, and Y. Hirayama, Conductance quantization and shot noise of a double-layer quantum point contact, Phys. Rev. B 101, 115401 (2020).
  64. P. Wójcik and J. Adamowski, Spin filtering effect generated by the inter-subband spin-orbit coupling in the bilayer nanowire with the quantum point contact, Sci. Rep. 7, 45346 (2017).
  65. Y. A. Bychkov and É. I. Rashba, Properties of a 2D electron gas with lifted spectral degeneracy, Pis'ma Zh. Eksp. Teor. Fiz. 39, 66 (1984) [JETP Lett. 39, 78 (1984)].
  66. E. A. de A. e. Silva, G. C. La Rocca, and F. Bassani, Spin-orbit splitting of electronic states in semiconductor asymmetric quantum wells, Phys. Rev. B 55, 16293 (1997).

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Phys. Rev. B 114, L051402– Published 7 July, 2026
  • Received 30 December 2025
  • Revised 17 April 2026
  • Accepted 15 June 2026
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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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