Advanced Quantum Magnetic Materials for Quantum Information Technologies

Project funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under project No. 09I03-03-V04-00403.

This project focuses on investigating the unconventional quantum properties of frustrated Heisenberg spin systems, drawing inspiration from novel quantum materials. The primary aim is to explore the robustness of quantum entanglement in the Heisenberg spin model under increasing temperature and magnetic field conditions, which holds significance for quantum computing and information processing. Additionally, the project seeks to comprehensively characterize the long-range entanglement of a prototypical frustrated Heisenberg spin system with a quantum spin-liquid ground state, as well as to investigate the suitability and effectiveness of using such systems for reliable quantum information storage from the perspective of bound mognons in high-field region.

Research aims:

1)To provide a complete description of the quantum spin liquid in material-inspired two-dimensional quantum Heisenberg spin system. The main emphasis will be laid on those candidates of quantum spin-liquid materials, which display extraordinary quantum features due to their closeness to a quantum critical point.  Particular task of this aim is to clarify thermally-assisted suppression of long-range quantum entanglement within the quantum spin-liquid state in zero as well as nonzero magnetic field. 

2) Thoroughly investigate the Heisenberg frustrated spin system with bound magnons emerging in the high-field regime. The unique properties of these bound magnons can play a crucial role in terms of the system’s potential for quantum information storage. By studying the dynamics and characteristics of bound magnons within the Heisenberg spin system, we will determine the suitability and effectiveness of using such systems for reliable quantum information storage.

Methodology: In solving the project, a combination of sophisticated analytical and numerical methods will be utilized, such as the theory of localized magnons, variational techniques, level spectroscopy method, Quantum Monte Carlo (QMC), QMC in a dimer basis, full exact diagonalization (ED), Lanczos method, and Density Matrix Renormalization Group (DMRG).

Events:

We are looking forward to welcoming researchers to Košice, Slovakia (26–29 October 2025) for the final meeting of the CNRS international network “Strongly correlated electron systems as advanced magnetocaloric materials.”

The conference will feature cutting-edge talks and discussions on frustrated magnetism, magnetocaloric effects, and advanced materials — plus enjoy an engaging program and great networking opportunities.

More info at: https://coolmag2025.sciencesconf.org/

New publication in Zeitschrift für Naturforschung A

Our recent work on frustrated quantum magnetism has been published in Zeitschrift für Naturforschung A. The study investigates a spin-1/2 Heisenberg antiferromagnet on a distorted diamond-decorated honeycomb lattice, revealing a rich variety of quantum phases and field-induced transitions. By combining analytical and advanced numerical methods, we uncover magnetization plateaus and complex quantum states arising from geometric frustration, contributing to a deeper understanding of quantum magnetic materials.

New publication in Quantum Science and Technology
Our recent results on cluster-based Haldane states and bound magnons in the spin-1 Heisenberg diamond chain have been published in Quantum Science and Technology. The work combines analytical and numerical approaches and contributes to the project objective of understanding magnon-based quantum states relevant for quantum information technologies.

New publication in Entropy
Our recent work on finite-size effects in statistical mechanics has been published in Entropy, Special Issue: “Ising Model—100 Years Old and Still Attractive”. The study develops an exact transfer-matrix approach for spin-1/2 Ising chains with open boundary conditions and systematically compares their magnetic properties with the conventional periodic case. The results reveal how boundary conditions and parity influence magnetization plateaus and magnetic response functions, providing new insight into finite-size effects in low-dimensional spin systems.

Pending publication in Physica A
Our recent work on exact phase transitions in lattice-statistical models is currently under review for the Physica A, Special Issue: “50 Years of Physica A: a Tribute to Hans Capel”. The study presents an exact solution of a mixed-spin Ising model on the Lieb lattice in a magnetic field, revealing continuous, discontinuous, and reentrant thermal phase transitions through a combination of analytical methods and Monte Carlo simulations.

Pending publication in Physical Review Letters
Our recent work introduces the first realization of emergent Kasteleyn physics in an SU(2)-symmetric quantum Heisenberg antiferromagnet. By mapping a frustrated quantum spin system onto an effective monomer–dimer model, the study reveals an arbitrarily sharp Kasteleyn crossover and establishes a bridge between frustrated quantum magnetism and classical dimer criticality. The manuscript is currently under review at Physical Review Letters.


Conference presentations

The results of the project have been presented at several international conferences and workshops through invited and contributed talks as well as poster presentations.

Follow-up research funding.
One of the objectives of the project was to establish new international collaborations and develop follow-up research activities. This objective has been achieved through a funded Slovak–Ukrainian bilateral APVV research project. The new project ensures the continuation of the scientific collaboration and supports further research on frustrated quantum magnetism.