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Sep 5, 2022

Researchers succeed in coupling two types of electron-hole pairs

Posted by in categories: materials, particle physics

Two-dimensional van der Waals materials have been the focus of work by numerous research groups for some time. Standing just a few atomic layers thick, these structures are produced in the laboratory by combining atom-thick layers of different materials (in a process referred to as “atomic Lego”). Interactions between the stacked layers allow the heterostructures to exhibit properties that the individual constituents lack.

Two-layered molybdenum disulfide is one such van der Waals material, in which electrons can be excited using a suitable experimental setup. These negatively charged particles then leave their position in the , leaving behind a positively charged hole, and enter the conduction band. Given the different charges of electrons and holes, the two are attracted to one another and form what is known as a quasiparticle. The latter is also referred to as an electron-hole pair, or exciton, and can move freely within the material.

In two-layered molybdenum disulfide, excitation with light produces two different types of electron-hole pairs: intralayer pairs, in which the electron and hole are localized in the same layer of the material, and interlayer pairs, whose hole and electron are located in different layers and are therefore spatially separate from one another.

Sep 5, 2022

Prynt Stealer Contains a Backdoor to Steal Victims’ Data Stolen

Posted by in category: cybercrime/malcode

Researchers discovered a private Telegram channel-based backdoor in the information stealing malware, dubbed Prynt Stealer, which its developer added with the intention of secretly stealing a copy of victims’ exfiltrated data when used by other cybercriminals.

“While this untrustworthy behavior is nothing new in the world of cybercrime, the victims’ data end up in the hands of multiple threat actors, increasing the risks of one or more large scale attacks to follow,” Zscaler ThreatLabz researchers Atinderpal Singh and Brett Stone-Gross said in a new report.

Prynt Stealer, which came to light earlier this April, comes with capabilities to log keystrokes, steal credentials from web browsers, and siphon data from Discord and Telegram. It’s sold for $100 for a one-month license and $900 for a lifetime subscription.

Sep 5, 2022

TikTok Denies Data Breach Reportedly Exposing Over 2 Billion Users’ Information

Posted by in category: cybercrime/malcode

TikTok has denied reports of a data breach after a hacker group claimed to have gained access to information on two billion of its users.

Sep 5, 2022

Ransomware Attackers Abuse Genshin Impact Anti-Cheat System to Disable Antivirus

Posted by in category: cybercrime/malcode

Ransomware hackers are abusing an anti-cheat system driver for the extremely popular game Genshin Impact to disable antivirus software.

Sep 5, 2022

Fake Antivirus and Cleaner Apps Caught Installing SharkBot Android Banking Trojan

Posted by in categories: cybercrime/malcode, finance, information science, robotics/AI

The droppers are designed to drop a new version of SharkBot, dubbed V2 by Dutch security firm ThreatFabric, which features an updated command-and-control (C2) communication mechanism, a domain generation algorithm (DGA), and a fully refactored codebase.

Fox-IT said it discovered a newer version 2.25 on August 22, 2022, that introduces a function to siphon cookies when victims log in to their bank accounts, while also removing the ability to automatically reply to incoming messages with links to the malware for propagation.

Sep 5, 2022

Samsung Admits Data Breach that Exposed Details of Some U.S. Customers

Posted by in category: cybercrime/malcode

Samsung suffered a data breach that exposed some personal information from its U.S. customers.

Sep 5, 2022

Time: Do the past, present, and future exist all at once?

Posted by in categories: biological, neuroscience, physics

Everything we do as living organisms is dependent, in some capacity, on time. The concept is so complex that scientists still argue whether it exists or if it is an illusion.

In this video, astrophysicist Michelle Thaller, science educator Bill Nye, author James Gleick, and neuroscientist Dean Buonomano discuss how the human brain perceives of the passage of time, the idea in theoretical physics of time as a fourth dimension, and the theory that space and time are interwoven.

Thaller illustrates Einstein’s theory of relativity, Buonomano outlines eternalism, and all the experts touch on issues of perception, definition, and experience.

Sep 5, 2022

New Horizons Toward Supercapacitor Energy Devices

Posted by in categories: bioengineering, energy, nanotechnology

Because of their unique physical, photonic, thermal, and electronic capabilities, two-dimensional (2D) nanostructures have exhibited tremendous promise in the domains of bioengineering, sensing, and energy storage.

Study: Two Dimensional Silicene Nanosheets: A New Choice of Electrode Material for High-Performance Supercapacitor. Image Credit: Quardia/Shutterstock.com.

Nonetheless, combining silicon-based nanomaterials into high-performance power storage systems remains a largely undeveloped subject because of the complex manufacturing process. New work published in the journal ACS Applied Materials & Interfaces hope to address this problem by effectively integrating silicene nanosheets into a high-voltage supercapacitor.

Sep 5, 2022

Dual-polarization two-dimensional valley photonic crystals

Posted by in category: quantum physics

The introduction of topology in photonic systems has attracted considerable attention not only for the elaborate molding of light but also for its practical applications in novel photonic devices. Originally, the quantum Hall effect of light was realized in photonic crystals (PCs) by introducing external electric or magnetic fields to break the time-reversal symmetry (TRS).

Instead of breaking the TRS, the quantum spin-Hall effect of light has been achieved in TRS-preserved systems where photonic pseudospins can be constructed. Recently, the valley Hall effect of light has been realized by introducing the binary valley degree of freedom (DoF) into photonic systems. One of the vital features of the valley Hall effect is the nontrivial photonic band gap, which is characterized by the nonzero valley Chern number.

Furthermore, valley-dependent edge modes are supported at the domain wall which consists of two PCs with opposite-valley Chern numbers. The valley Hall effect of light is commonly realized in a triangular-lattice PC with broken mirror symmetry or in a honeycomb-lattice PC with broken spatial inversion symmetry, and it is compatible with existing nanophotonic fabrication technique.

Sep 5, 2022

Nanoscale pillars as a building block for future information technology

Posted by in categories: nanotechnology, particle physics, quantum physics

Researchers from Linköping University and the Royal Institute of Technology in Sweden have proposed a new device concept that can efficiently transfer the information carried by electron spin to light at room temperature—a stepping stone toward future information technology. They present their approach in an article in Nature Communications.

Light and electron charge are the main media for information processing and transfer. In the search for information technology that is even faster, smaller and more energy-efficient, scientists around the globe are exploring another property of —their spin. Electronics that exploit both the spin and the charge of the electron are called “spintronics.”

Like the Earth, an electron spins around its own axis, either clockwise or counterclockwise. The handedness of the rotation is referred to as spin-up and spin-down states. In spintronics, the two states represent the binary bits and thus carry information. The information encoded by these can be converted by a -emitting device into light, which then carries the information over a long distance through fiber optics. The transfer of quantum information opens the possibility to exploit both and light, and the interaction between them, a technology known as “opto-spintronics.”