Spin-resolved oscilloscope for charge and spin signals
Masayuki Hashisaka
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 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.
Original publication
Other news from the department science
These products might interest you
DAWN® by Wyatt Technology
The instrument for Multi-Angle Light Scattering (MALS): The DAWN® from Wyatt Technology
The world's most advanced light scattering instrument for absolute characterization of macromolecules
AZURA Analytical HPLC by KNAUER
Maximize your analytical efficiency with customized HPLC system solutions
Let your application define your analytical system solution
Get the chemical industry in your inbox
From now on, don't miss a thing: Our newsletter for the chemical industry, analytics, lab technology and process engineering brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.