Researchers at the Center for Theoretical Physics of Complex Systems (PCS), within the Institute for Basic Science (IBS, South Korea), and colleagues have reported on a new phenomenon, called Acoustoelectric Effect, occurring in 2- D materials, similar to graphing. This study will be published in Physical review letters and brings new insights into the study of valleytronics.
In acoustic electronics, surface acoustic waves (SAWs) are used to generate electrical currents. In this study, the team of theoretical physicists modeled the propagation of SAWs in emerging 2-D materials, such as monohydric molybdenum disulfide (MoS).2). SAWs drag MoS2 electrodes (and gaps), making an electric current with conventional and unconventional components. The latter consists of two contributions: a warping-based stream and a Hall stream. The first is directional-dependent, is related to "so-called" counts – electrons & # 39; local energy minima – and resembles one of the mechanisms that explain photovoltaic effects of 2-D materials exposed to light. The second is due to a specific effect (Berry phase) that has an influence on the velocity of these electrodes traveling as a group and resulting in intriguing phenomena such as anomalous and quantum Hall effects.
The team analyzed the characteristics of an acoustic-electric current, suggesting a way to independently run and measure conventional, warping and Hall currents. This allows you to simultaneously utilize both optical and acoustic techniques to control the propagation of carriers in new 2-D materials, creating new logical devices.
The researchers are interested in checking the physical properties of these ultra-thin systems, especially those that are free to move in two dimensions, but tightly in & # 39; containing a third. By limiting the parameters of & nbsp; electrodes, in & # 39; Especially their momentum, spider, and drop, it will be possible to research technologies outside silicon electronics. For example, MoS2 has two district valleys, which can be potentially used in a future for bit storage and processing, making it an ideal material to immerse in valleytronics.
"Our theory opens a way to manipulate valley transport through acoustic methods, and to extend the application of dental effects to acousto-electronic devices," explains Ivan Savenko, leader of Light-Matter Interaction in Nanostructures Team at PCS.
Spontaneous spin polarization demonstrated in a two-dimensional material
A. V. Kalameitsev et al., Valley Acoustoelectric Effect, Physical review letters (2019). DOI: 10.1103 / PhysRevLett.122.256801
Unconventional phenomena triggered by acoustic waves in 2-D materials (2019, July 23)
July 23, 2019 pick up
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