### Abstract

Recent experiments and theories have suggested that strong spin-orbit coupling effects in certain band insulators can give rise to a new phase of quantum matter, the so-called topological insulator, which can show macroscopic quantum-entanglement effects. Such systems feature two-dimensional surface states whose electrodynamic properties are described not by the conventional Maxwell equations but rather by an attached axion field, originally proposed to describe interacting quarks. It has been proposed that a topological insulator with a single Dirac cone interfaced with a superconductor can form the most elementary unit for performing fault-tolerant quantum computation. Here we present an angle-resolved photoemission spectroscopy study that reveals the first observation of such a topological state of matter featuring a single surface Dirac cone realized in the naturally occurring Bi 2 Se 3 class of materials. Our results, supported by our theoretical calculations, demonstrate that undoped Bi 2 Se 3 can serve as the parent matrix compound for the long-sought topological device where in-plane carrier transport would have a purely quantum topological origin. Our study further suggests that the undoped compound reached via n-to-p doping should show topological transport phenomena even at room temperature.

Original language | English (US) |
---|---|

Pages (from-to) | 398-402 |

Number of pages | 5 |

Journal | Nature Physics |

Volume | 5 |

Issue number | 6 |

DOIs | |

State | Published - Jun 2009 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Nature Physics*,

*5*(6), 398-402. https://doi.org/10.1038/nphys1274

**Observation of a large-gap topological-insulator class with a single Dirac cone on the surface.** / Xia, Y.; Qian, D.; Hsieh, D.; Wray, L.; Pal, A.; Lin, H.; Bansil, A.; Grauer, D.; Hor, Y. S.; Cava, R. J.; Hasan, M. Z.

Research output: Contribution to journal › Article

*Nature Physics*, vol. 5, no. 6, pp. 398-402. https://doi.org/10.1038/nphys1274

}

TY - JOUR

T1 - Observation of a large-gap topological-insulator class with a single Dirac cone on the surface

AU - Xia, Y.

AU - Qian, D.

AU - Hsieh, D.

AU - Wray, L.

AU - Pal, A.

AU - Lin, H.

AU - Bansil, A.

AU - Grauer, D.

AU - Hor, Y. S.

AU - Cava, R. J.

AU - Hasan, M. Z.

PY - 2009/6

Y1 - 2009/6

N2 - Recent experiments and theories have suggested that strong spin-orbit coupling effects in certain band insulators can give rise to a new phase of quantum matter, the so-called topological insulator, which can show macroscopic quantum-entanglement effects. Such systems feature two-dimensional surface states whose electrodynamic properties are described not by the conventional Maxwell equations but rather by an attached axion field, originally proposed to describe interacting quarks. It has been proposed that a topological insulator with a single Dirac cone interfaced with a superconductor can form the most elementary unit for performing fault-tolerant quantum computation. Here we present an angle-resolved photoemission spectroscopy study that reveals the first observation of such a topological state of matter featuring a single surface Dirac cone realized in the naturally occurring Bi 2 Se 3 class of materials. Our results, supported by our theoretical calculations, demonstrate that undoped Bi 2 Se 3 can serve as the parent matrix compound for the long-sought topological device where in-plane carrier transport would have a purely quantum topological origin. Our study further suggests that the undoped compound reached via n-to-p doping should show topological transport phenomena even at room temperature.

AB - Recent experiments and theories have suggested that strong spin-orbit coupling effects in certain band insulators can give rise to a new phase of quantum matter, the so-called topological insulator, which can show macroscopic quantum-entanglement effects. Such systems feature two-dimensional surface states whose electrodynamic properties are described not by the conventional Maxwell equations but rather by an attached axion field, originally proposed to describe interacting quarks. It has been proposed that a topological insulator with a single Dirac cone interfaced with a superconductor can form the most elementary unit for performing fault-tolerant quantum computation. Here we present an angle-resolved photoemission spectroscopy study that reveals the first observation of such a topological state of matter featuring a single surface Dirac cone realized in the naturally occurring Bi 2 Se 3 class of materials. Our results, supported by our theoretical calculations, demonstrate that undoped Bi 2 Se 3 can serve as the parent matrix compound for the long-sought topological device where in-plane carrier transport would have a purely quantum topological origin. Our study further suggests that the undoped compound reached via n-to-p doping should show topological transport phenomena even at room temperature.

UR - http://www.scopus.com/inward/record.url?scp=67650262991&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67650262991&partnerID=8YFLogxK

U2 - 10.1038/nphys1274

DO - 10.1038/nphys1274

M3 - Article

VL - 5

SP - 398

EP - 402

JO - Nature Physics

JF - Nature Physics

SN - 1745-2473

IS - 6

ER -