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arXiv 1709.08968cond-mat.mes-hall
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具有可调能量分布的按需电子源

On-demand electron source with tunable energy distribution

Yue Yin

摘要:

提出了一种在电压脉冲电子源中控制电子-空穴激发的方案,该方案可以通过将电压驱动欧姆接触连接到量子霍尔边缘通道来实现。已经知道,电子-空穴激发可以通过洛伦兹脉冲来抑制,从而产生无噪声的电子流。我们表明,而不是洛伦兹脉冲,驱动通过电压脉冲$V(t) = 2 \frac{\hbar}{e} \sqrt{\frac{\sqrt{3}}π k_{\rm B} T_h} \arctanh( \frac{t - t_0}{t_0} )$与持续时间$t_0$,电子-空穴激发可以调谐,使相应的能量分布的发射电子遵循费米分布与温度$T_{\rm D} = \sqrt{ T^2_{\rm S} + T^2_{\rm h} }$,与$T_{\rm S}$是欧姆接触中的电子温度。这种费米分布可以在不引入额外的能量弛豫机制的情况下建立,并且可以通过散粒噪声测温技术检测,这有助于介观系统中热输运和退相干的研究。

英文摘要:

We propose a scheme to manipulate the electron-hole excitation in the voltage pulse electron source, which can be realized by a voltage-driven Ohmic contact connecting to a quantum hall edge channel. It has been known that the electron-hole excitation can be suppressed via Lorentzian pulses, leading to noiseless electron current. We show that, instead of the Lorentzian pulses, driven via the voltage pulse $V(t) = 2 \frac{\hbar}{e} \sqrt{\frac{\sqrt{3}}π k_{\rm B} T_h} \arctanh( \frac{t - t_0}{t_0} )$ with duration $t_0$, the electron-hole excitation can be tuned so that the corresponding energy distribution of the emitted electrons follows the Fermi distribution with temperature $T_{\rm D} = \sqrt{ T^2_{\rm S} + T^2_{\rm h} }$, with $T_{\rm S}$ being the electron temperature in the Ohmic contact. Such Fermi distribution can be established without introducing additional energy relaxation mechanism and can be detected via shot noise thermometry technique, making it helpful in the study of thermal transport and decoherence in mesoscopic system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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