Cyclotron resonance spectroscopy of a high-mobility two-dimensional electron gas from 0.4 to 100 K at high filling factors

Journal Article · Thu Oct 01 00:00:00 EDT 2015 · Sandia journal manuscript; Not yet accepted for publication

OSTI ID:1427259

Curtis, Jeremy A. ^[1]; Tokumoto, Takahisa ^[1]; Cherian, Judy G. ^[2]; Kuno, J. ^[3]; Reno, John L. ^[4]; McGill, Stephen A. ^[2]; Karaiskaj, Denis ^[5]; Hilton, David J. ^[1]

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1. Univ. of Alabama, Birmingham, AL (United States)
2. Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab)
3. Rice Univ., Houston, TX (United States)
4. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
5. Univ. of South Florida, Tampa, FL (United States)

We have studied the cyclotron mobility of a Landau-quantized two-dimensional electron gas as a function of temperature (0.4 --100 K) at a fixed magnetic field (1.25 T) using terahertz time-domain spectroscopy in a sample with a low frequency mobility of μ_dc = 3.6 x 10⁶ cm² V^-1 s^-1 and a carrier concentration of ns = 2 x 10₆ cm^-2. The low temperature mobility in this sample results from both impurity scattering and acoustic deformation potential scattering, with μ$$-1\atop{CR}$$ ≈ (2.1 x 10⁵ cm² V^-1 s^-1)^-1 + (3.8 x 10^-8 V sK^-1 cm^-2 x T)^-1 at low temperatures. Above 50 K, the cyclotron oscillations show a strong reduction in both the oscillation amplitude and lifetime that is dominated by the contribution due to polar optical phonons. These results suggest that electron dephasing times as long as ~ 300 ps are possible even at this high lling factor (v = 6:6) in higher mobility samples (> 10⁷ cm² V^-1 s^-1) that have lower impurity concentrations and where the cyclotron mobility at this carrier concentration would be limited by acoustic deformation potential scattering.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1427259
• Report Number(s): SAND--2015-9127J; 608007
• Journal Information: Sandia journal manuscript; Not yet accepted for publication, Journal Name: Sandia journal manuscript; Not yet accepted for publication; ISSN 9999-0014
• Publisher: Sandia
• Country of Publication: United States
• Language: English