Waveform measurement of charge- and spin-density wavepackets in a chiral Tomonaga-Luttinger liquid
Waveform measurement of charge- and spin-density wavepackets in a chiral Tomonaga-Luttinger liquid
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DOI：
10.1038/nphys4062
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发表时间：
2017-06-01
期刊：
影响因子：
19.6
通讯作者：
Fujisawa, T.
中科院分区：
文献类型：
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作者：
Hashisaka, M.;Hiyama, N.;Fujisawa, T.
与自由电子系统相比，一维（1D）电子系统中的Tomonaga-Luttinger （TL）液体作为独立的实体承载电荷和自旋激发（1-4）。当一个电子被注入TL液体时，它会转变成电荷密度和自旋密度的波包，它们以不同的群速度传播，并相互远离。这个过程被称为自旋-电荷分离，是TL物理学的标志。虽然自旋-电荷分离已经在各种一维系统的动量域或频域测量中进行了探测（5-9），但作为TL行为的直接表现，分离激发的波形一直等待着测量。在这里，我们提出了包含量子霍尔边缘通道（9-13）的手性TL液体中伪自旋-电荷分离过程的波形测量。电荷和伪自旋密度波形是通过利用自旋分辨采样范围捕获的，该采样范围记录了激发的自旋向上或向下分量。该实验技术为一维电子系统的时间演化提供了完整的信息，不仅包括TL特征模的传播，还包括它们在实际设备中的衰变（14）。
In contrast to a free-electron system, a Tomonaga-Luttinger (TL) liquid in a one-dimensional (1D) electron system hosts charge and spin excitations as independent entities(1-4). Whenan electron is injected into a TL liquid, it transforms into charge- and spin-density wavepackets that propagate at different group velocities and move away from each other. This process, knownas spin-charge separation, is the hallmark of TL physics. While spin-charge separation has been probed in momentum- or frequency-domain measurements in various 1D systems(5-9), waveforms of separated excitations, which are a direct manifestation of the TL behaviour, have been long awaited to be measured. Here, we present a waveform measurement for the pseudospin-charge separation process in a chiral TL liquid comprising quantum Hall edge channels(9-13). The charge- and pseudospin-density waveforms are captured by utilizing a spin-resolved sampling scope that records the spin-up or - down component of the excitations. This experimental technique provides full information for time evolution of the 1D electron system, including not only propagation of TL eigenmodes but also their decay in a practical device(14).