H2020Индивидуална стипендия2018–2020

PRESS-CHESS-KHS · The effect of pressure and chemical substitution on the Kitaev Heisenberg system alpha-RuCl3

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2018-06-01 → 2020-08-29
Финансиране от ЕС: 159 461 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Магнитните свойства на материала $\alpha\text{-RuCl}_3$ се променят чрез прилагане на натиск и химически замени. Разбирането на тези процеси помага при разработването на топологични квантови компютри.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

The effect of pressure and chemical substitution on the Kitaev Heisenberg system alpha-RuCl3

In magnetic materials, magnetic moments carried by the electrons interact with each other and their collective behavior accounts for the magnetic properties of materials, leading to a large variety of magnetic phenomenon. Frustrated magnets are materials, where not all magnetic interactions can be simultaneously satisfied. The magnetic frustration gives rise to the competition between various magnetic phases. Among them the quantum spin liquid state attracts much attention due to possible applications for topological quantum computation. In this phase a strong quantum entanglement and fractionalized excitations occurs, while long-range magnetic order is absent down to zero temperature. In this project we focused on one particular frustrated magnet, i.e., alpha-RuCl3. The magnetism in this material is close to the Kitaev model: An exactly solvable theoretical model, which harbors a quantum spin liquid state as magnetic ground state with fractionalized Majorana-fermion quasiparticle as excitations . In this model, Ising-like magnetic interactions named Kitaev interactions couple for two neighboring magnetic moments the spin component parallel to the link/bond between the two neighboring magnetic moments to each other. α-RuCl3 is a Mott insulator with a 2D layered structure of edge-sharing RuCl6 octahedra arranged in a honeycomb lattice. The spin and orbital moment of the ruthenium sites are strongly coupled by the spin-orbit interaction leading to the formation of so-called isospins Jeff=1/2. α-RuCl3 is close to the realization of the Kitaev model, since a ferromagnetic Kitaev interactions is the strongest magnetic interaction in this system, however, other magnetic interactions are present as well: Heisenberg interactions and off-diagonal couplings. Despite the proximity to the Kitaev model, alpha-RuCl3 orders magnetically at a temperature TN=7.5 K. However, this long-range magnetic order can be suppressed by the application of a magnetic field within the honeycomb plane at the critical field Hc ~ 7 T. While magnetic fields much higher than Hc = 7 T induce a field-polarized state, the occurrence of a field-induced quantum spin liquid state in a narrow field interval remains under debate. In this research project, the Kitaev magnet alpha-RuCl3 was tuned by the application of hydrostatic pressure and by chemical substitution and intercalation. The aim was to test the stability of the magnetic order and to probe the different magnetic states such as quantum spin liquid states, which compete with this magnetic order and can be induced by these modifications of alpha-RuCl3.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

The Kitaev model on a honeycomb lattice has caused an abiding fascination due to its quantum spin liquid ground state, which is relevant to register information in matter and specifically for topological quantum computation. Here, alpha-RuCl3 is believed to be the prime material to-date to harbor such a quantum spin liquid phase. Recent studies from 2016 showed that a magnetic field can induce the highly desired quantum spin liquid state. As a new route towards the realization of this state in alpha-RuCl3, this research project will concentrate on tuning the magnetic properties by the application of hydrostatic pressure and chemical substitution. Their influence on the Kitaev-like interaction, the magnetic ground state, and the field-induced quantum spin liquid state will be studied by magnetization and thermodynamic techniques.During the time of his PhD, the applicant acquired a strong knowledge on magnetism and experimental skills in high-pressure and low-temperature measurements. This makes the applicant perfectly adapted for this research project, which will be conducted under unique conditions at the host institution. At the IFW Dresden high-quality single crystals and world-class experimental facilities (such as a unique pressure cell) are available. Via the solid experience of the applicant in high-pressure physics, this pressure cell will be improved to an even higher accuracy in the research project.The applicant will follow trainings to study research integrity, develop his own leadership, construct this career development plan and learn German to obtain a clear visibility to continue an excellent career in academic research. He will disseminate his results among the scientific community through publications in high-ranking scientific journals, and participation in conferences. He will also communicate them to the public through a Science Night. In the future, the obtained results will eventually lead to the realization of quantum computing.

Оригинален текст от CORDIS (на английски).

Участници

LEIBNIZ INSTITUT FUR FESTKORPER UND WERKSTOFFORSCHUNG DRESDEN EV · DresdenКоординаторГермания