Endicott J, Patanè A, Ibáñez J, Eaves L, Bissiri M, Hopkinson M, Airey R, Hill G
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2003 Sep 19;91(12):126802. doi: 10.1103/PhysRevLett.91.126802. Epub 2003 Sep 16.
We use magnetotunneling spectroscopy to explore the admixing of the extended GaAs conduction band states with the localized N-impurity states in dilute GaAs(1-y)N(y) quantum wells. In our resonant tunneling diodes, electrons can tunnel into the N-induced E- and E+ subbands in a GaAs(1-y)N(y) quantum well layer, leading to resonant peaks in the current-voltage characteristics. By varying the magnetic field applied perpendicular to the current direction, we can tune an electron to tunnel into a given k state of the well; since the applied voltage tunes the energy, we can map out the form of the energy-momentum dispersion curves of E- and E+. The data reveal that for a small N content (approximately 0.1%) the E- and E+ subbands are highly nonparabolic and that the heavy effective mass E+ states have a significant Gamma-conduction band character even at k=0.
我们使用磁隧穿光谱来探究稀 GaAs(1 - y)N(y)量子阱中扩展的 GaAs 导带态与局域化 N 杂质态的混合情况。在我们的共振隧穿二极管中，电子能够隧穿进入 GaAs(1 - y)N(y)量子阱层中由 N 诱导产生的 E - 和 E + 子带，从而在电流 - 电压特性中产生共振峰。通过改变垂直于电流方向施加的磁场，我们可以调节电子隧穿进入阱的给定 k 态；由于施加的电压可调节能量，我们能够描绘出 E - 和 E + 的能量 - 动量色散曲线的形式。数据表明，对于低 N 含量（约 0.1%），E - 和 E + 子带具有高度非抛物线特性，并且即使在 k = 0 时，重有效质量 E + 态也具有显著的 Γ 导带特征。
