Russian prof finds experimental proof for Zeeman spin-orbit coupling in antiferromagnetic

A NUST MISIS professor was part of an international research team that has found evidence for the existence of the Zeeman spin-orbit coupling in antiferromagnetic conductors. This work may pave the way for the next generation of electronics. The study was published in npj Quantum Materials.

The electron possesses two fundamental properties: charge and spin. Conventional electronic devices use only the charge of electrons for information processing. In recent years, an enormous research effort has been focused on building fundamentally new electronic devices (often called "spintronic devices") that would specifically exploit spin properties in addition to charge degrees of freedom. Transfer from conventional electronics to spintronics technology opens the possibilities to construct devices with high storage density and fast operation. The two-component nature of spin-based systems makes them potentially applicable for quantum supercomputing.

The current effort in designing spintronic devices is focusing on understanding and making use of spin-orbit coupling, an interaction between the orbital angular momentum and the spin angular momentum of an individual particle, such as an electron. However, spin-orbit coupling occurring in many compounds is often weak or its emergence requires the use of heavy components. One way to overcome spin-orbit coupling-related challenges could be the use of antiferromagnetic. A spin-orbit coupling of an unusual nature termed Zeeman spin-orbit coupling is expected to manifest itself in a wide range of ferromagnetic conductors. Being proportional to the applied magnetic field, the coupling is tunable. Yet, experimental proof of this phenomenon has been lacking.

The collaboration of a NUST MISIS physicist with colleagues from Germany, France, and Japan produced, for the first time, experimental evidence of Zeeman spin-orbit coupling in two very different layered conductors: an organic antiferromagnetic superconductor, and a prominent electron-doped superconductor that belongs to the family of high-temperature cuprate superconducting materials. Obtained on two very different materials, the results of this work demonstrate the generic nature of the Zeeman spin-orbit coupling. In addition to its fundamental importance, the Zeeman spin-orbit coupling opens new possibilities for spin manipulation, much sought after in the current effort to harness electron spin for future spintronic applications. Laboratory equipment at the NUST MISIS Department of Theoretical Physics and Quantum Technologies  CREDIT Sergey Gnuskov/NUST MISIS

"The Zeeman spin-orbit coupling can be significantly stronger than other known kinds of spin-orbit coupling, thus providing new avenues for the development of fundamentally new electronic devices," noted Pavel Grigoriev, Professor at the NUST MISIS Department of Theoretical Physics and Quantum Technologies, senior researcher at Landau Institute for Theoretical Physics.

SAIC acquires Koverse

Science Applications International Corp. has entered into a definitive agreement to acquire Koverse, a software company that provides a data management platform enabling artificial intelligence (AI) and machine learning on complex, sensitive data.

Founded in 2012 by former U.S. intelligence community AI and high-volume data processing experts, Koverse is a 16-person, Seattle-based company that delivers scalable, secure, and high-performing solutions to federal and commercial customers. Koverse solves one of the most difficult and time-consuming challenges in developing AI tools: organizing structured and unstructured data from multiple sources based on a user’s individual attributes and permissions. This capability is essential for government and military organizations where data access requires various clearance levels, as well as regulated commercial industries such as healthcare, financial services, and pharmaceuticals.

Koverse’s unique mission expertise and secure platform are already used in the most demanding environments, and SAIC will bring this offering at scale to security-conscious customers across government.

“I am excited to welcome Koverse to team SAIC. Koverse’s impressive track record among its commercial and government customers coupled with its unique data management platform makes it a rare gem that enriches our current data modernization offerings,” said SAIC CEO Nazzic Keene. “We see many opportunities for Koverse across the federal defense, civilian, and intelligence communities. Together, we bring a passion for service, innovation, and integrity that will further drive digital transformation and innovation.”

“This transaction will drive faster innovation and enable organizations to transform how they use complex and sensitive data,” said Jon Matsuo, president and CEO of Koverse. “Joining forces with SAIC creates a direct channel to include Koverse as the underlying data platform in large, important pieces of the emerging defense and national intelligence community mission.”

 

Russian researchers develop a program to find cipher vulnerabilities

Anastasia Malashina, a doctoral student at HSE University, has proposed a new method to assess vulnerabilities in encryption systems, which is based on a brute-force search of possible options of symbol deciphering. The algorithm was also implemented in a program, which can be used to find vulnerabilities in ciphers. The results of the study were published in a paper 'Software development for the study of natural language characteristics'.

Most online messages are sent in encrypted form since open communication channels are not protected from data interception. Messengers, cloud services, banking systems--all of these need to be protected from data breaches. The problem of data encryption is one of the main issues for cryptographers.

The problem of cipher vulnerability search is always a relevant one. To avoid hacks, it is necessary to reinforce the cipher protection from leaks and to test encryption systems for vulnerabilities. Малашина 53b7c

All ciphers can be split into two big classes: block ciphers and stream ciphers. Stream data has a big advantage: they provide an acceptable speed of information transmission, suitable for images and videos.

A stream cipher is based on a combination of data with random sequencing on a special algorithm. Special keys are used for this kind of ciphering. There are many requirements to the keys so that the data coded with their use can be produced and stored. Meanwhile, it is not always possible to ensure that a reliable key is used. That's why stream ciphering systems need to be pre-tested for vulnerabilities.

"I was interested in not only suggesting an algorithm that is able to detect the initial text of a transmitted message, but to find opportunities to restore the text both theoretically and practically in a direct way, without finding the key,' said Anastasia Malashina.

To find vulnerabilities, she used a method that helps assess the possibility of restoring separate parts of a message without a key, in case a vulnerable cipher is used or there is a leak in the communication channel.

The algorithm uses information about possible options for each of the ciphered symbols in the initial message and brutally searches the values for all the other symbols. In case the initial cipher has a vulnerability, this method helps detect it.

The suggested algorithm was implemented in a special program, part of which has recently been patented. This program helps assess encryption systems' reliability and breach risks in case of data leaks.

"During my study, I looked at a corpus of social-political texts, and an open corpus of the Russian language. A statistical analysis of dictionaries helped me assess the entropy of texts, for which I later assessed the possibility of partial deciphering. Furthermore, corpus-based dictionaries are used in the experimental part of the study to implement a dictionary-based attack. Similar results for the English language were reached based on the iWeb corpus," said Malashina.