Insulating conduction in Sn/Si(111): Possibility of a Mott insulating ground state and metallization/localization induced by carrier doping

Hirahara, Toru; Komorida, Taku; Gu, Yan; Nakamura, Fumi; Idzuchi, Hiroshi; Morikawa, Hirofumi; Hasegawa, Shuji

doi:10.1103/physrevb.80.235419

Cited by 15 publications

(9 citation statements)

References 29 publications

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“…Possible reasons for the gap opening are suggested to be formation of the charge-density waves or Mott-Hubbard insulator ground state. Similar discrepancy between metallic surface band structure revealed by ARPES [12] and nonmetallic electron transport behavior [13], a hard gap singularity at E F by STS at low temperatures [14] was also observed for the Si(111)-…”

Section: Introductionmentioning

confidence: 77%

Electron correlation effects in transport and tunneling spectroscopy of theSi(111)−7×7surface

2015

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Electronic properties of the Si(111)-7×7 surface are studied using four-and two-probe conductivity measurements and tunneling spectroscopy. We demonstrate that the temperature dependence of the surface conductivity corresponds to the Efros-Shklovskii law at least in 10 − 100 K temperature range. The energy gap at the Fermi level observed in tunneling spectroscopy measurements at T ≥ 5 K vanishes by thermal fluctuations at T ≈ 30 K, without any sign of the metal-insulator transition. We show that the low-temperature energy gap observed by the tunneling spectroscopy technique is actually the consequence of the Coulomb blockade effect.

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Section: Introductionmentioning

confidence: 77%

Electron correlation effects in transport and tunneling spectroscopy of theSi(111)−7×7surface

2015

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“…Transport measurements on Sn/Si(111) by a four tip STM have also conclusively shown that resistivity increases when temperature decreases. 17 At variance with the Sn/Ge(111) case, the Sn/Si(111) surface maintains a √ 3 symmetry in the whole temperature range from room temperature to 6 K. Theoretical calculations support that both Sn/Ge(111) and Sn/Si(111) are Mott insulators at low temperature, predicting even magnetism and superconductivity. 18 Magnetic ordering at low temperatures has been recently reported for Sn/Si(111).…”

Section: Introductionmentioning

confidence: 85%

Competing charge ordering and Mott phases in a correlated Sn/Ge(111) two-dimensional triangular lattice

et al. 2013

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We take advantage of complementary high-resolution experimental techniques and theoretical tools to get insight into the α-Sn/Ge(111) triangular lattice surface consisting of sp electrons. We report a (3 × 3) phase, characterized by a charge ordering settled by electronic correlation, which appears between the known metallic-(3 × 3) and Mott insulator phases. We identify the atomistic mechanism behind the stabilization of this phase and interpret these findings on the basis of theoretical calculations. We disentangle the role of the various degrees of freedom in the stability of the different phases found and describe the stepwise surface changes between the metallic and Mott insulating phases.

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“…Among others, charge density waves (CDW) [e.g., α-Pb/Ge(111)-( √ 3× √ 3) [1,2]] or Mott phases [α-Sn/Si(111)-( √ 3× √ 3) [3]], driven by strong electron-phonon and electron-electron interactions, were discovered for various (sub)monolayer phases. While many of these surface reconstructions come along with metal-insulator transitions, dense monolayers (MLs) of Pb and In on Si(111) reveal superconductivity with critical temperatures below 4 K [4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Spin-resolved band structure of a densely packed Pb monolayer on Si(111)

et al. 2017

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Monolayer structures of Pb on Si(111) attracted recently considerable interest as superconductivity was found in these truly two-dimensional (2D) structures. In this study, we analyzed the electronic surface band structure of the so-called striped incommensurate Pb phase with 4 3 ML coverage by means of spin-resolved photoemission spectroscopy. Our results fully agree with density functional theory calculations done by Ren et al. [Phys. Rev. B 94, 075436 (2016)]. We observe a local Zeeman-type splitting of a fully occupied and spin-polarized surface band at the K √ 3 points. The growth of this densely packed Pb structure results in the formation of imbalanced rotational domains, which triggered the detection of C 3v symmetry forbidden spin components for surface states around the Fermi energy. Moreover, the Fermi surface of the metallic surface state of this phase is Rashba spin split and revealed a pronounced warping. However, the 2D nesting vectors are incommensurate with the atomic structure, thus keeping this system rather immune against charge density wave formation and possibly enabling a superconducting behavior.

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Insulating conduction in Sn/Si(111): Possibility of a Mott insulating ground state and metallization/localization induced by carrier doping

Cited by 15 publications

References 29 publications

Electron correlation effects in transport and tunneling spectroscopy of theSi(111)−7×7surface

Electron correlation effects in transport and tunneling spectroscopy of theSi(111)−7×7surface

Competing charge ordering and Mott phases in a correlated Sn/Ge(111) two-dimensional triangular lattice

Spin-resolved band structure of a densely packed Pb monolayer on Si(111)

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