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Spin-resolved oscilloscope for charge and spin signals

Basic measuring instrument for future plasmonics and spintronics

Date:
March 13, 2017
Source:
Tokyo Institute of Technology
Summary:
Researchers have developed a 'spin-resolved oscilloscope.'
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Researchers at the Tokyo Institute of Technology and Nippon Telegraph and Telephone Corporation have developed a "spin-resolved oscilloscope." This device is a basic measuring instrument for plasmonics and spintronics, which are key technologies for future electronics applications. The coupling of light and electronic charges in plasmonics will pave the way for ultra-high-speed information processing, whereas spintronics will provide low-energy-consumption technology in a highly information-oriented society. The spin-resolved oscilloscope pioneers future "spin-plasmonics," where ultra-high-speed low-energy-consumption devices will be achieved.

An electron has charge and spin, and both the charge- and spin-density excitations in an electronic system can be utilized in information processing. The dynamics of charge-density waves has been investigated in plasmonics, and that of spin-density waves has been studied in the field of spintronics. However, less effort has been devoted to combining these two technologies and to developing the expected ultra-high-speed and low-energy-consumption devices. To date, a major obstacle preventing the promotion of this research field has been the lack of a measuring instrument that is sensitive to both charge and spin.

In their recent paper, published in Nature Physics, Dr. Masayuki Hashisaka at Tokyo Tech and colleagues reported a "spin-resolved oscilloscope" that enables measurement of the waveforms of both charge and spin signals in electronic devices. An oscilloscope is a basic measuring instrument used in electronics; however, conventional oscilloscopes do not facilitate both charge and spin measurement.

The "charge signal" is the total charge of the spin-up and -down electron densities. Further, the "spin signal" is the difference between the spin-up and -down electron densities. Both these signals traveling in a semiconductor device can be detected by the spin-resolved oscilloscope, which is composed of a spin filter and nanometer-scale time-resolved charge detectors. The spin filter separates the spin-up and -down electrons, while the time-resolved charge detector measures the waveforms of the charge-density waves. By combining these spintronic and plasmonic devices, the spin-resolved oscilloscope is established.

Using this spin-resolved oscilloscope, Hashisaka and colleagues demonstrated waveform measurements of charge- and spin-density wavepackets in a semiconductor device. They succeeded in observing the spin-charge-separation process in a one-dimensional (1D) electronic system composed of quantum Hall edge channels, which is a prototypical system for the investigation of 1D electron dynamics. This was the first experiment in which a single spin-charge-separation waveform measurement allowed estimation of all the relevant system parameters. Further, this observation manifests not only the usefulness of the spin-resolved oscilloscope, but also the possibility for developing novel plasmonic and spintronic devices based on 1D semiconductor materials.

The spin-resolved oscilloscope will promote investigations in both plasmonics and spintronics; for example, this device will aid studies of electron dynamics in various 1D systems. In addition, the spin-resolved oscilloscope will pave the way for future "spin-plasmonics," where ultra-high-speed and low-energy-consumption devices will be achieved.


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Materials provided by Tokyo Institute of Technology. Note: Content may be edited for style and length.


Journal Reference:

  1. M. Hashisaka, N. Hiyama, T. Akiho, K. Muraki, T. Fujisawa. Waveform measurement of charge- and spin-density wavepackets in a chiral Tomonaga–Luttinger liquid. Nature Physics, 2017; DOI: 10.1038/nphys4062

Cite This Page:

Tokyo Institute of Technology. "Spin-resolved oscilloscope for charge and spin signals: Basic measuring instrument for future plasmonics and spintronics." ScienceDaily. ScienceDaily, 13 March 2017. <www.sciencedaily.com/releases/2017/03/170313135035.htm>.
Tokyo Institute of Technology. (2017, March 13). Spin-resolved oscilloscope for charge and spin signals: Basic measuring instrument for future plasmonics and spintronics. ScienceDaily. Retrieved March 23, 2017 from www.sciencedaily.com/releases/2017/03/170313135035.htm
Tokyo Institute of Technology. "Spin-resolved oscilloscope for charge and spin signals: Basic measuring instrument for future plasmonics and spintronics." ScienceDaily. www.sciencedaily.com/releases/2017/03/170313135035.htm (accessed March 23, 2017).