Thickness-dependent bulk properties and weak antilocalization effect in topological insulator Bi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>2</mml:mn></mml:msub></mml:math>Se<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>3</mml:mn></mml:msub></mml:math>

Kim, Yong Seung; Brahlek, Matthew; Bansal, Namrata; Edrey, Eliav; Kapilevich, Gary A.; Iida, Keiko; Tanimura, Makoto; Horibe, Y.; Cheong, Sang‐Wook; Oh, Seongshik

doi:10.1103/physrevb.84.073109

Cited by 298 publications

(310 citation statements)

References 35 publications

Supporting

Mentioning

272

Contrasting

Order By: Relevance

“…In contrast to previous studies of WAL in TI thin films [15][16][17][18][19][20][21][22] where strong surface to bulk scattering dominates inter-channel coupling, here we report WAL measurements in gate-tuned, bulkinsulating Bi 2 Se 3 thin films where we expect negligible surfacebulk scattering. We find that the WAL behaviour in TI regime is governed by the ratio of t j to the inter-surface tunnelling time t t ¼ h/2D, where h is Planck's constant and D is the hybridization gap induced by inter-surface tunnelling 12,14 .…”

mentioning

confidence: 48%

Coherent topological transport on the surface of Bi2Se3

et al. 2013

View full text Add to dashboard Cite

The two-dimensional surface of the three-dimensional topological insulator is in the symplectic universality class and should exhibit perfect weak antilocalization reflected in positive weak-field magneto-resistance. Previous studies in topological insulator thin films suffer from high level of bulk n-type doping making quantitative analysis of weak antilocalization difficult. Here we measure the magneto-resistance of bulk-insulating Bi 2 Se 3 thin films as a function of film thickness and gate-tuned carrier density. For thick samples, the magnitude of weak antilocalization indicates two decoupled (top and bottom) symplectic surfaces. On reducing thickness, we observe first a crossover to a single symplectic channel, indicating coherent coupling of top and bottom surfaces via interlayer tunnelling, and second, a complete suppression of weak antilocalization. The first crossover is governed by the ratio of phase coherence time to the inter-surface tunnelling time, and the second crossover occurs when the hybridization gap becomes comparable to the disorder strength.

show abstract

mentioning

confidence: 48%

Coherent topological transport on the surface of Bi2Se3

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Figure 2(d) shows the STM topography of a nominal 3QL thick film with flat terraces and 1 nm step heights, corresponding to one QL. Figure 3(a) shows the two-terminal resistance measured during sample cool-down, which displays an insulating behavior with resistance increasing about two orders of magnitude between room temperature and 5 K. Similar insulating behavior has always been seen in ultrathin Bi 2 Se 3 films, which could be due to strong interactions [25], or Anderson localization [26,27]. To test the gating ability of the TI/STO device, we measured the 2-terminal resistance through the 3QL film vs. gate voltage (Fig.…”

mentioning

confidence: 88%

Scanning tunneling microscopy of gate tunable topological insulator Bi2Se3thin films

Zhang

Levy

et al. 2013

Phys. Rev. B

View full text Add to dashboard Cite

Electrical field control of the carrier density of topological insulators (TI) has greatly expanded the possible practical use of these materials. However, the combination of low temperature local probe studies and a gate tunable TI device remains challenging. We have overcome this limitation by scanning tunneling microscopy and spectroscopy measurements on in-situ molecular beam epitaxy growth of Bi 2 Se 3 films on SrTiO 3 substrates with pre-patterned electrodes. Using this gating method, we are able to shift the Fermi level of the top surface states by ≈250 meV on a 3 nm thick Bi 2 Se 3 device. We report field effect studies of the surface state dispersion, band gap, and electronic structure at the Fermi level.

show abstract

“…This is because the top and bottom surfaces are connected though the bulk channel to form a single diffusive transport channel. 173,186,[235][236][237] Remember, as long as the thickness is shorter than L which is usually of the order of 100-1000 nm in TIs, electrons can diffusively travel from the bottom surface state to the top surface state though the bulk state using three different Fermi surfaces without losing the phase memory. Figure 19 shows an example of the weak antilocalization behavior observed in a series of MBE-grown Bi 2 Se 3 thin films with varying thickness, in which % À1=2 was consistently observed unless the films are too thin.…”

Section: Weak Anti-localization Effectmentioning

confidence: 99%

Topological Insulator Materials

2013

View full text Add to dashboard Cite

Topological insulators represent a new quantum state of matter which is characterized by peculiar edge or surface states that show up due to a topological character of the bulk wave functions. This review presents a pedagogical account on topological insulator materials with an emphasis on basic theory and materials properties. After presenting a historical perspective and basic theories of topological insulators, it discusses all the topological insulator materials discovered as of May 2013, with some illustrative descriptions of the developments in materials discoveries in which the author was involved. A summary is given for possible ways to confirm the topological nature in a candidate material. Various synthesis techniques as well as the defect chemistry that are important for realizing bulk-insulating samples are discussed. Characteristic properties of topological insulators are discussed with an emphasis on transport properties. In particular, the Dirac fermion physics and the resulting peculiar quantum oscillation patterns are discussed in detail. It is emphasized that proper analyses of quantum oscillations make it possible to unambiguously identify surface Dirac fermions through transport measurements. The prospects of topological insulator materials for elucidating novel quantum phenomena that await discovery conclude the review.

show abstract

Thickness-dependent bulk properties and weak antilocalization effect in topological insulator Bi2Se3

Cited by 298 publications

References 35 publications

Coherent topological transport on the surface of Bi2Se3

Coherent topological transport on the surface of Bi2Se3

Scanning tunneling microscopy of gate tunable topological insulator Bi2Se3thin films

Topological Insulator Materials

Contact Info

Product

Resources

About