Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?

Tsvelik, A. M.; Yevtushenko, O. M.

doi:10.1088/1367-2630/ab82bb

Title: Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?

Abstract

We study the phase diagram and transport properties of arbitrarily doped quantum wires functionalized by magnetic adatoms. The appropriate theoretical model for these systems is a dense one-dimensional Kondo lattice (KL) which consists of itinerant electrons interacting with localized quantum magnetic moments. We discover the novel phase of the locally helical metal where transport is protected from a destructive influence of material imperfections. Paradoxically, such a protection emerges without a need of the global helicity, which is inherent in all previously studied helical systems and requires breaking the spin-rotation symmetry. We explain the physics of this protection of the new type, find conditions, under which it emerges, and discuss possible experimental tests. Our results pave the way to the straightforward realization of the protected ballistic transport in quantum wires made of various materials.

Authors:

; Yevtushenko, O. M.

Publication Date:: Tue May 05 00:00:00 EDT 2020

Research Org.:: Brookhaven National Laboratory (BNL), Upton, NY (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; German Research Foundation (DFG)

OSTI Identifier:: 1617395

Alternate Identifier(s):: OSTI ID: 1614976

Report Number(s):: BNL-213834-2020-JAAM
Journal ID: ISSN 1367-2630

Grant/Contract Number:: SC0012704; YE 157/2-1&2

Resource Type:: Published Article

Journal Name:: New Journal of Physics

Additional Journal Information:: Journal Name: New Journal of Physics Journal Volume: 22 Journal Issue: 5; Journal ID: ISSN 1367-2630

Publisher:: IOP Publishing

Country of Publication:: United Kingdom

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; quantum wires; protected transport; magnetic adatoms; Kondo lattice

Citation Formats


                    Tsvelik, A. M., and Yevtushenko, O. M. Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?.  United Kingdom: N. p., 2020. 
Web.  doi:10.1088/1367-2630/ab82bb.

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                    Tsvelik, A. M., & Yevtushenko, O. M. Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?.  United Kingdom.  https://doi.org/10.1088/1367-2630/ab82bb

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                    Tsvelik, A. M., and Yevtushenko, O. M. Tue .  
"Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?".  United Kingdom.  https://doi.org/10.1088/1367-2630/ab82bb.

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@article{osti_1617395,

  title        = {Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?},

  author       = {Tsvelik, A. M. and Yevtushenko, O. M.},

  abstractNote = {We study the phase diagram and transport properties of arbitrarily doped quantum wires functionalized by magnetic adatoms. The appropriate theoretical model for these systems is a dense one-dimensional Kondo lattice (KL) which consists of itinerant electrons interacting with localized quantum magnetic moments. We discover the novel phase of the locally helical metal where transport is protected from a destructive influence of material imperfections. Paradoxically, such a protection emerges without a need of the global helicity, which is inherent in all previously studied helical systems and requires breaking the spin-rotation symmetry. We explain the physics of this protection of the new type, find conditions, under which it emerges, and discuss possible experimental tests. Our results pave the way to the straightforward realization of the protected ballistic transport in quantum wires made of various materials.},

  doi          = {10.1088/1367-2630/ab82bb},

  journal      = {New Journal of Physics},

  number       = 5,

  volume       = 22,

  place        = {United Kingdom},

  year         = {Tue May 05 00:00:00 EDT 2020},

  month        = {Tue May 05 00:00:00 EDT 2020}

}

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Works referenced in this record:

The one-dimensional Kondo lattice model studied by the density matrix renormalization group method
journal, January 1999

Shibata, Naokazu; Ueda, Kazuo
Journal of Physics: Condensed Matter, Vol. 11, Issue 2
DOI: 10.1088/0953-8984/11/2/002

Ferromagnetism in the strong-coupling regime of the one-dimensional Kondo-lattice model
journal, December 1992

Sigrist, Manfred; Tsunetsugu, Hirokazu; Ueda, Kazuo
Physical Review B, Vol. 46, Issue 21
DOI: 10.1103/physrevb.46.13838

Magnetic and non-magnetic ground states of the Kondo lattice
journal, June 1991

Fazekas, P.; M�ller-Hartmann, E.
Zeitschrift f�r Physik B Condensed Matter, Vol. 85, Issue 2
DOI: 10.1007/bf01313231

Friedel oscillations in the one-dimensional Kondo lattice model
journal, November 1996

Shibata, Naokazu; Ueda, Kazuo; Nishino, Tomotoshi
Physical Review B, Vol. 54, Issue 19
DOI: 10.1103/physrevb.54.13495

One-dimensional Kondo lattice model as a Tomonaga-Luttinger liquid
journal, July 1997

Shibata, Naokazu; Tsvelik, Alexei; Ueda, Kazuo
Physical Review B, Vol. 56, Issue 1
DOI: 10.1103/physrevb.56.330

Interaction induced topological protection in one-dimensional conductors: Interaction induced topological protection in one-dimensional conductors
journal, January 2017

Kainaris, Nikolaos; Santos, Raul A.; Gutman, D. B.
Fortschritte der Physik, Vol. 65, Issue 6-8
DOI: 10.1002/prop.201600054

High-resolution studies of the Majorana atomic chain platform
journal, November 2016

Feldman, Benjamin E.; Randeria, Mallika T.; Li, Jian
Nature Physics, Vol. 13, Issue 3
DOI: 10.1038/nphys3947

Quantum Spin Hall Insulator State in HgTe Quantum Wells
journal, November 2007

Konig, M.; Wiedmann, S.; Brune, C.
Science, Vol. 318, Issue 5851, p. 766-770
DOI: 10.1126/science.1148047

Conductance through a helical state in an Indium antimonide nanowire
journal, September 2017

Kammhuber, J.; Cassidy, M. C.; Pei, F.
Nature Communications, Vol. 8, Issue 1
DOI: 10.1038/s41467-017-00315-y

Observation of a Majorana zero mode in a topologically protected edge channel
journal, June 2019

Jäck, Berthold; Xie, Yonglong; Li, Jian
Science, Vol. 364, Issue 6447
DOI: 10.1126/science.aax1444

Doped Kondo chain, a heavy Luttinger liquid
journal, April 2018

Khait, Ilia; Azaria, Patrick; Hubig, Claudius
Proceedings of the National Academy of Sciences, Vol. 115, Issue 20
DOI: 10.1073/pnas.1719374115

Carbon nanotubes in electric and magnetic fields
journal, August 2011

Klinovaja, Jelena; Schmidt, Manuel J.; Braunecker, Bernd
Physical Review B, Vol. 84, Issue 8
DOI: 10.1103/physrevb.84.085452

Ferromagnetic state in the one-dimensional Kondo lattice model
journal, October 2012

Peters, Robert; Kawakami, Norio
Physical Review B, Vol. 86, Issue 16
DOI: 10.1103/physrevb.86.165107

Signatures of interaction-induced helical gaps in nanowire quantum point contacts
journal, March 2017

Heedt, S.; Traverso Ziani, N.; Crépin, F.
Nature Physics, Vol. 13, Issue 6
DOI: 10.1038/nphys4070

Localized spin ordering in Kondo lattice models
journal, January 2002

McCulloch, I. P.; Juozapavicius, A.; Rosengren, A.
Physical Review B, Vol. 65, Issue 5
DOI: 10.1103/physrevb.65.052410

Finite-temperature conductance of strongly interacting quantum wire with a nuclear spin order
journal, March 2017

Aseev, Pavel P.; Klinovaja, Jelena; Loss, Daniel
Physical Review B, Vol. 95, Issue 12
DOI: 10.1103/physrevb.95.125440

Néel orders, Haldane gap, and Kondo singlet phase in the anisotropic Kondo chain
journal, February 1995

Shibata, Naokazu; Ishii, Chikara; Ueda, Kazuo
Physical Review B, Vol. 51, Issue 6
DOI: 10.1103/physrevb.51.3626

Antiferromagnetic nuclear spin helix and topological superconductivity in ${}^{13}C$ nanotubes
journal, December 2015

Hsu, Chen-Hsuan; Stano, Peter; Klinovaja, Jelena
Physical Review B, Vol. 92, Issue 23
DOI: 10.1103/physrevb.92.235435

Chiral Spin Order in Kondo-Heisenberg Systems
journal, December 2017

Tsvelik, A. M.; Yevtushenko, O. M.
Physical Review Letters, Vol. 119, Issue 24
DOI: 10.1103/physrevlett.119.247203

Coulomb interaction effects and electron spin relaxation in the one-dimensional Kondo lattice model
journal, February 2011

Smerat, Sebastian; Schoeller, Herbert; McCulloch, Ian P.
Physical Review B, Vol. 83, Issue 8
DOI: 10.1103/physrevb.83.085111

Small Fermi surface in the one-dimensional Kondo lattice model
journal, May 2002

Xavier, J. C.; Novais, E.; Miranda, E.
Physical Review B, Vol. 65, Issue 21
DOI: 10.1103/physrevb.65.214406

Synthetic spin–orbit interaction for Majorana devices
journal, August 2019

Desjardins, M. M.; Contamin, L. C.; Delbecq, M. R.
Nature Materials, Vol. 18, Issue 10
DOI: 10.1038/s41563-019-0457-6

Visualizing heavy fermions emerging in a quantum critical Kondo lattice
journal, June 2012

Aynajian, Pegor; da Silva Neto, Eduardo H.; Gyenis, András
Nature, Vol. 486, Issue 7402
DOI: 10.1038/nature11204

Observation of a one-dimensional spin–orbit gap in a quantum wire
journal, March 2010

Quay, C. H. L.; Hughes, T. L.; Sulpizio, J. A.
Nature Physics, Vol. 6, Issue 5
DOI: 10.1038/nphys1626

Dynamic response functions and helical gaps in interacting Rashba nanowires with and without magnetic fields
journal, December 2016

Pedder, Christopher J.; Meng, Tobias; Tiwari, Rakesh P.
Physical Review B, Vol. 94, Issue 24
DOI: 10.1103/physrevb.94.245414

Integrable perturbations of ZN parafermion models and the O(3) sigma model
journal, November 1991

Fateev, V. A.; Zamolodchikov, Al. B.
Physics Letters B, Vol. 271, Issue 1-2
DOI: 10.1016/0370-2693(91)91283-2

Scaling the Kondo lattice
journal, July 2008

Yang, Yi-feng; Fisk, Zachary; Lee, Han-Oh
Nature, Vol. 454, Issue 7204
DOI: 10.1038/nature07157

Phase diagram of the Kondo lattice model
journal, May 1993

Ueda, Kazuo; Tsunetsugu, Hirokazu; Sigrist, Manfred
Physica B: Condensed Matter, Vol. 186-188
DOI: 10.1016/0921-4526(93)90573-o

The one-dimensional Kondo lattice model at partial band filling
journal, November 2004

Gulácsi *, Miklós
Advances in Physics, Vol. 53, Issue 7
DOI: 10.1080/00018730412331313997

Semiclassical solution of one dimensional model of Kondo insulator
journal, February 1994

Tsvelik, A. M.
Physical Review Letters, Vol. 72, Issue 7
DOI: 10.1103/physrevlett.72.1048

Transport in helical Luttinger liquid with Kondo impurities
journal, December 2015

Yevtushenko, Oleg M.; Wugalter, Ari; Yudson, Vladimir I.
EPL (Europhysics Letters), Vol. 112, Issue 5
DOI: 10.1209/0295-5075/112/57003

Low energy properties of the Kondo chain in the RKKY regime
journal, May 2016

Schimmel, D. H.; Tsvelik, A. M.; Yevtushenko, O. M.
New Journal of Physics, Vol. 18, Issue 5
DOI: 10.1088/1367-2630/18/5/053004

Ballistic One-Dimensional Holes with Strong g -Factor Anisotropy in Germanium
journal, July 2018

Mizokuchi, R.; Maurand, R.; Vigneau, F.
Nano Letters, Vol. 18, Issue 8
DOI: 10.1021/acs.nanolett.8b01457

The Kondo lattice and weak antiferromagnetism
journal, July 1977

Doniach, S.
Physica B+C, Vol. 91
DOI: 10.1016/0378-4363(77)90190-5

Exact solution of the O(3) nonlinear σ-model
journal, March 1985

Wiegmann, P. B.
Physics Letters B, Vol. 152, Issue 3-4
DOI: 10.1016/0370-2693(85)91171-2

Edge transport in the trivial phase of InAs/GaSb
journal, July 2016

Nichele, Fabrizio; Suominen, Henri J.; Kjaergaard, Morten
New Journal of Physics, Vol. 18, Issue 8
DOI: 10.1088/1367-2630/18/8/083005

Dimerization Induced by the RKKY Interaction
journal, June 2003

Xavier, J. C.; Pereira, R. G.; Miranda, E.
Physical Review Letters, Vol. 90, Issue 24
DOI: 10.1103/physrevlett.90.247204

Spin-selective Peierls transition in interacting one-dimensional conductors with spin-orbit interaction
journal, July 2010

Braunecker, Bernd; Japaridze, George I.; Klinovaja, Jelena
Physical Review B, Vol. 82, Issue 4
DOI: 10.1103/physrevb.82.045127

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Title: Transport in magnetically doped one-dimensional wires: can the helical protection emerge without the global helicity?

Abstract

Citation Formats

The one-dimensional Kondo lattice model studied by the density matrix renormalization group method journal, January 1999

Ferromagnetism in the strong-coupling regime of the one-dimensional Kondo-lattice model journal, December 1992

Magnetic and non-magnetic ground states of the Kondo lattice journal, June 1991

Friedel oscillations in the one-dimensional Kondo lattice model journal, November 1996

One-dimensional Kondo lattice model as a Tomonaga-Luttinger liquid journal, July 1997

Interaction induced topological protection in one-dimensional conductors: Interaction induced topological protection in one-dimensional conductors journal, January 2017

High-resolution studies of the Majorana atomic chain platform journal, November 2016

Quantum Spin Hall Insulator State in HgTe Quantum Wells journal, November 2007

Conductance through a helical state in an Indium antimonide nanowire journal, September 2017

Observation of a Majorana zero mode in a topologically protected edge channel journal, June 2019

Doped Kondo chain, a heavy Luttinger liquid journal, April 2018

Carbon nanotubes in electric and magnetic fields journal, August 2011

Ferromagnetic state in the one-dimensional Kondo lattice model journal, October 2012

Signatures of interaction-induced helical gaps in nanowire quantum point contacts journal, March 2017

Localized spin ordering in Kondo lattice models journal, January 2002

Finite-temperature conductance of strongly interacting quantum wire with a nuclear spin order journal, March 2017

Néel orders, Haldane gap, and Kondo singlet phase in the anisotropic Kondo chain journal, February 1995

Antiferromagnetic nuclear spin helix and topological superconductivity in C 13 nanotubes journal, December 2015

Chiral Spin Order in Kondo-Heisenberg Systems journal, December 2017

Coulomb interaction effects and electron spin relaxation in the one-dimensional Kondo lattice model journal, February 2011

Small Fermi surface in the one-dimensional Kondo lattice model journal, May 2002

Synthetic spin–orbit interaction for Majorana devices journal, August 2019

Visualizing heavy fermions emerging in a quantum critical Kondo lattice journal, June 2012

Observation of a one-dimensional spin–orbit gap in a quantum wire journal, March 2010

Dynamic response functions and helical gaps in interacting Rashba nanowires with and without magnetic fields journal, December 2016

Integrable perturbations of ZN parafermion models and the O(3) sigma model journal, November 1991

Scaling the Kondo lattice journal, July 2008

Phase diagram of the Kondo lattice model journal, May 1993

The one-dimensional Kondo lattice model at partial band filling journal, November 2004

Semiclassical solution of one dimensional model of Kondo insulator journal, February 1994

Transport in helical Luttinger liquid with Kondo impurities journal, December 2015

Low energy properties of the Kondo chain in the RKKY regime journal, May 2016

Ballistic One-Dimensional Holes with Strong g -Factor Anisotropy in Germanium journal, July 2018

The Kondo lattice and weak antiferromagnetism journal, July 1977

Exact solution of the O(3) nonlinear σ-model journal, March 1985

Edge transport in the trivial phase of InAs/GaSb journal, July 2016

Dimerization Induced by the RKKY Interaction journal, June 2003

Spin-selective Peierls transition in interacting one-dimensional conductors with spin-orbit interaction journal, July 2010

The one-dimensional Kondo lattice model studied by the density matrix renormalization group method
journal, January 1999

Ferromagnetism in the strong-coupling regime of the one-dimensional Kondo-lattice model
journal, December 1992

Magnetic and non-magnetic ground states of the Kondo lattice
journal, June 1991

Friedel oscillations in the one-dimensional Kondo lattice model
journal, November 1996

One-dimensional Kondo lattice model as a Tomonaga-Luttinger liquid
journal, July 1997

Interaction induced topological protection in one-dimensional conductors: Interaction induced topological protection in one-dimensional conductors
journal, January 2017

High-resolution studies of the Majorana atomic chain platform
journal, November 2016

Quantum Spin Hall Insulator State in HgTe Quantum Wells
journal, November 2007

Conductance through a helical state in an Indium antimonide nanowire
journal, September 2017

Observation of a Majorana zero mode in a topologically protected edge channel
journal, June 2019

Doped Kondo chain, a heavy Luttinger liquid
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Carbon nanotubes in electric and magnetic fields
journal, August 2011

Ferromagnetic state in the one-dimensional Kondo lattice model
journal, October 2012

Signatures of interaction-induced helical gaps in nanowire quantum point contacts
journal, March 2017

Localized spin ordering in Kondo lattice models
journal, January 2002

Finite-temperature conductance of strongly interacting quantum wire with a nuclear spin order
journal, March 2017

Néel orders, Haldane gap, and Kondo singlet phase in the anisotropic Kondo chain
journal, February 1995

Antiferromagnetic nuclear spin helix and topological superconductivity in ${}^{13}C$ nanotubes
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Chiral Spin Order in Kondo-Heisenberg Systems
journal, December 2017

Coulomb interaction effects and electron spin relaxation in the one-dimensional Kondo lattice model
journal, February 2011

Small Fermi surface in the one-dimensional Kondo lattice model
journal, May 2002

Synthetic spin–orbit interaction for Majorana devices
journal, August 2019

Visualizing heavy fermions emerging in a quantum critical Kondo lattice
journal, June 2012

Observation of a one-dimensional spin–orbit gap in a quantum wire
journal, March 2010

Dynamic response functions and helical gaps in interacting Rashba nanowires with and without magnetic fields
journal, December 2016

Integrable perturbations of ZN parafermion models and the O(3) sigma model
journal, November 1991

Scaling the Kondo lattice
journal, July 2008

Phase diagram of the Kondo lattice model
journal, May 1993

The one-dimensional Kondo lattice model at partial band filling
journal, November 2004

Semiclassical solution of one dimensional model of Kondo insulator
journal, February 1994

Transport in helical Luttinger liquid with Kondo impurities
journal, December 2015

Low energy properties of the Kondo chain in the RKKY regime
journal, May 2016

Ballistic One-Dimensional Holes with Strong g -Factor Anisotropy in Germanium
journal, July 2018

The Kondo lattice and weak antiferromagnetism
journal, July 1977

Exact solution of the O(3) nonlinear σ-model
journal, March 1985

Edge transport in the trivial phase of InAs/GaSb
journal, July 2016

Dimerization Induced by the RKKY Interaction
journal, June 2003

Spin-selective Peierls transition in interacting one-dimensional conductors with spin-orbit interaction
journal, July 2010