Tuttle, Gary

Profile Picture
Email Address
gtuttle@iastate.edu
Birth Date
Title
Associate Professor Emeritus
Academic or Administrative Unit
Organizational Unit
Electrical and Computer Engineering

The Department of Electrical and Computer Engineering (ECpE) contains two focuses. The focus on Electrical Engineering teaches students in the fields of control systems, electromagnetics and non-destructive evaluation, microelectronics, electric power & energy systems, and the like. The Computer Engineering focus teaches in the fields of software systems, embedded systems, networking, information security, computer architecture, etc.

History
The Department of Electrical Engineering was formed in 1909 from the division of the Department of Physics and Electrical Engineering. In 1985 its name changed to Department of Electrical Engineering and Computer Engineering. In 1995 it became the Department of Electrical and Computer Engineering.

Dates of Existence
1909-present

Historical Names

  • Department of Electrical Engineering (1909-1985)
  • Department of Electrical Engineering and Computer Engineering (1985-1995)

Related Units
About
Profile Link
https://dr.lib.iastate.edu/handle/20.500.12876/99513
ORCID iD

Filters

2012 1
1
1
1
1
1
Reset filters

Settings
Document Type: article × Start date: 2012 × End date: 2012 ×

Search Results

Now showing 1 - 1 of 1
No Thumbnail Available
Publication

Weak Anti-localization and Quantum Oscillations of Surface States in Topological Insulator Bi2Se2Te

2012-10-11 , Bao, Lihong , He, Liang , Meyer, Nicholas , Tuttle, Gary , Kou, Xufeng , Zhang, Peng , Chen, Zhi-gang , Fedorov, Alexei , Riedemann, Trevor , Lograsso, Thomas , Wang, Kang , Xiu, Faxian , Ames National Laboratory

Topological insulators, a new quantum state of matter, create exciting opportunities for studying topological quantum physics and for exploring spintronic applications due to their gapless helical metallic surface states. Here, we report the observation of weak anti-localization and quantum oscillations originated from surface states in Bi2Se2Te crystals. Angle-resolved photoemission spectroscopy measurements on cleaved Bi2Se2Te crystals show a well-defined linear dispersion without intersection of the conduction band. The measured weak anti-localization effect agrees well with the Hikami-Larkin-Nagaoka model and the extracted phase coherent length shows a power-law dependence with temperature ( ∼T−0.44), indicating the presence of the surface states. More importantly, the analysis of a Landau-level fan diagram of Shubnikov-de Hass oscillations yields a finite Berry phase of ∼0.42π, suggesting the Dirac nature of the surface states. Our results demonstrate that Bi2Se2Te can serve as a suitable topological insulator candidate for achieving intrinsic quantum transport of surface Dirac fermions.

View