论文标题
焦耳加热和通过修饰3 $ω$方法研究的低温温度下的二维电子气体的导热率
Joule heating and the thermal conductivity of a two-dimensional electron gas at cryogenic temperatures studied by modified 3$ω$ method
论文作者
论文摘要
在标准的交流锁定测量期间，二维电子气体（2DEG）应用AC电流$ i = \ sqrt {2} i_0 \ sin（ωt）$，电子温度$ t_e $ osciLLTATE ANCULAN频率$2Ω$振动，因为Joule the Joule the Joule the Joule the hation havile havie havie havie havile havile hation havile hation having $ \\ prepto prepto prepto prepto i^2 $ i^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $。我们已经表明，可以在振荡周期中的最高（$ t_ \ mathrm {h} $）和最低（$ t_ \ mathrm {l} $）温度，在振荡循环中，在低温温度下，利用第三量音（3 $ω$）的低温（3 $ω$）由AC $ i $ i $ i $ i $ i $ i $ i $ i $ i $ i i $ i i $ i i $ i i;振荡作为$ t_e $的度量。 The temperatures $T_\mathrm{H}$ and $T_\mathrm{L}$ thus obtained allow us to roughly evaluate the thermal conductivity $κ_{xx}$ of the 2DEG via the modified 3$ω$ method, in which the method originally devised for bulk materials is modified to be applicable to a 2DEG embedded in a semiconductor wafer.因此，发现推导的$κ_{xx} $与Wiedemann-Franz定律一致。该方法提供了一种仅使用标准霍尔杆设备和用于电阻测量的简单实验设置来访问$κ_{xx} $的方便方法。
During the standard ac lock-in measurement of the resistance of a two-dimensional electron gas (2DEG) applying an ac current $I = \sqrt{2} I_0 \sin(ωt)$, the electron temperature $T_e$ oscillates with the angular frequency $2 ω$ due to the Joule heating $\propto I^2$. We have shown that the highest ($T_\mathrm{H}$) and the lowest ($T_\mathrm{L}$) temperatures during a cycle of the oscillations can be deduced, at cryogenic temperatures, exploiting the third-harmonic (3$ω$) component of the voltage drop generated by the ac current $I$ and employing the amplitude of the Shubnikov-de Haas oscillations as the measure of $T_e$. The temperatures $T_\mathrm{H}$ and $T_\mathrm{L}$ thus obtained allow us to roughly evaluate the thermal conductivity $κ_{xx}$ of the 2DEG via the modified 3$ω$ method, in which the method originally devised for bulk materials is modified to be applicable to a 2DEG embedded in a semiconductor wafer. The $κ_{xx}$ thus deduced is found to be consistent with the Wiedemann-Franz law. The method provides a convenient way to access $κ_{xx}$ using only a standard Hall-bar device and the simple experimental setup for the resistance measurement.
