# Manuel Pereiro

Forskare vid Institutionen för fysik och astronomi; Materialteori

- E-post:
- manuel.pereiro@physics.uu.se
- Besöksadress:
- Ångströmlaboratoriet, Lägerhyddsvägen 1
- Postadress:
- Box 516

751 20 UPPSALA

Forskare vid Institutionen för fysik och astronomi; Materialteori; Materialteori

- E-post:
- manuel.pereiro@physics.uu.se
- Besöksadress:
- Ångströmlaboratoriet, Lägerhyddsvägen 1
- Postadress:
- Box 516

751 20 UPPSALA

Mer information visas för dig som medarbetare om du loggar in.

## Kort presentation

*Denna text finns inte på svenska, därför visas den engelska versionen.*

My research activities focus mainly on performing analytical calculations and modelling magnetic topological systems for realistic condensed matter applications. In particular, I was involved in predicting the existence of skyrmions in a kagome magnet. We also plan to use these tiny magnetic excitations to perform logical operation in a novel way. In that regards, Magnonics, as a novel research field, represents a hope for building smaller and lower-energy consumption logical devices.

## Biografi

*Denna text finns inte på svenska, därför visas den engelska versionen.*

I am currently working in the department of Physics and Astronomy, Uppsala University as a “Forskare”. I am a group member of the Atomistic Spin Dynamics (ASD) team, a subgroup in the Division of Materials Theory. The research in ASD is mainly devoted to the study and comprehension of the properties of magnetic materials at a very fundamental level. Thus, as the advancement in technology offers new possibilities to perform experimental studies at decreasing length scales and time scales, the importance of the dynamical response of individual atomic spins becomes more and more important. An atomistic spin dynamics method, where the time evolution of atomic spins are studied theoretically by solving the Landau-Lifshitz-Gilbert (LLG) equations, has been developed and has been successfully applied to a number of interesting cases by ASD team. The method has been implemented in a computer code, named UppASD as in Uppsala Atomistic Spin Dynamics, which is available to research groups globally. By combining the spin dynamics simulations with ab-initio calculations based on density functional theory, the ASD team obtain reliable spin models without a priori knowledge of the magnetic properties of the systems studied. From the ab-initio point of view, we have improved the techniques used to calculate the needed parameters for the spin models so that systems with non-collinear magnetic ordering and materials with strong electron correlations can now be treated more accurately.

## Forskning

*Denna text finns inte på svenska, därför visas den engelska versionen.*

I did my PhD studies at the University of Santiago de Compostela (Spain) studying magnetic, structural and optical properties of small metal clusters as well as theoretical problems related to the theory of special relativity and the giant magnetoresistance effect which end up in a fruitful PhD thesis with more that 55 publications in international journals of high impact factor. Among my publications, four were mentioned in the mass media for predicting the existence of substancial magnetism in clusters of diamagnetic atoms as, for example, silver atoms. As a consequence of that, I was awarded with the best PhD thesis in 2010 in the Faculty of Physics. During my PhD studies, I also initiated collaborations with international groups and after stays in Mexico and Poland, I was awarded with an European Thesis as well.

After that, I started a postdoc in the atomistic spin dynamics research group in the Division of Materials Theory at Uppsala University. Here, I collaborate with the members of the group in topics related to magnonics and skyrmionics, which are far from the research topics of my former PhD studies. I have local collaborations with experimental physicists at the Ångström laboratoriet as well as international collaborations with both theoretical and experimental physicists made by my own. In particular, during the postdoctoral research period, several collaborations have been initiated, both within Europe (mostly in Sweden in the department of physics and astronomy at Uppsala University) and outside. I have a collaboration with Prof. Angela Klautau at Federal University of Pará (Brazil) from where I was co-advising a PhD student, and since very recently I have initiated collaborations with the group of Prof. J. van den Brink at the Institute for Theoretical Solid State Physics, IFW Dresden in the topic of Kitaev materials like pyrochlore iridates. I am is also collaborating with Prof. Darío Alejandro Arena at the Department of Physics, University of South Florida in the topic of X-ray detected ferromagnetic resonance in magnetic trilayers. All these collaborations will end up in publications of high impact factor.

I have my own research interests and elaborate my own ideas as well as pursues independent routes compared with colleagues at the Department of Physics and Astronomy. In a broad sense, I am mainly devoted to the study and comprehension of the properties of magnetic materials at a very fundamental level. My research activities focus mainly on performing analytical calculations and modelling magnetic topological systems for realistic condensed matter applications.

Thus, as the advancement in technology offers new possibilities to perform experimental studies at decreasing length scales and time scales, the importance of the dynamical response of individual atomic spins becomes more and more important. An atomistic spin dynamics method, where the time evolution of atomic spins is studied theoretically by solving the Landau-Lifshitz-Gilbert equations, has been developed and has been successfully applied to a number of interesting cases by our team in Uppsala University.

The method has been implemented in a computer code and by combining the spin dynamics simulations with ab-initio calculations based on density functional theory, I can obtain reliable spin models without a priori knowledge of the magnetic properties of the studied systems. In particular, I was involved in predicting the existence of skyrmions in a kagome magnet. The article was published in the very prestigious journal Nature Communications. I also plan to use these tiny magnetic excitations to perform logical operations in a novel way and thus, be able to design totally new electronics based on magnetic circuits. This has the advantage of reduce power consumption and being more energy efficient than conventional Complementary Metal Oxide Semiconductor technology. Moreover, I am now planning to develop a new idea connecting the so called “crystals of time” with topological magnetic materials. As a result we were granted by Knut and Alice Wallenberg foundation in October 2018 to pursue forward within these topics. Another exciting project that I plan to pursue in the upcoming years is to find ways to efficiently extract the energy from the quantum vacuum by using the Casimir energy in layered chiral magnetic materials.

One point that emphasizes my independence is the fact that in my last accepted publications; I am placed in the last position of the authors’ list. Usually, in my research field, the last author in the list is considered as the one responsible for providing the main ideas of the article.

## Publikationer

### Senaste publikationer

- Dzyaloshinskii-Moriya interactions, Néel skyrmions and V
_{4}magnetic clusters in multiferroic lacunar spinel GaV_{4}S_{8}(2024) - Coupled atomistic spin-lattice simulations of ultrafast demagnetization in 3d ferromagnets (2024)
- Transmon probe for quantum characteristics of magnons in antiferromagnets (2023)
- Magnetism in AV
_{3}Sb_{5}(A = Cs, Rb, and K) (2023) - Magnetism in AV3Sb5 (A = Cs, Rb, K) (2023)

### Alla publikationer

#### Artiklar

- Dzyaloshinskii-Moriya interactions, Néel skyrmions and V
_{4}magnetic clusters in multiferroic lacunar spinel GaV_{4}S_{8}(2024) - Coupled atomistic spin-lattice simulations of ultrafast demagnetization in 3d ferromagnets (2024)
- Transmon probe for quantum characteristics of magnons in antiferromagnets (2023)
- Magnetism in AV
_{3}Sb_{5}(A = Cs, Rb, and K) (2023) - Magnetism in AV3Sb5 (A = Cs, Rb, K) (2023)
- Influence of Hard/Soft Layer Ordering on Magnetization Reversal of Bimagnetic Nanoparticles (2023)
- Tunable phonon-driven magnon-magnon entanglement at room temperature (2023)
- Influence of nonlocal damping on magnon properties of ferromagnets (2023)
- Metaheuristic conditional neural network for harvesting skyrmionic metastable states (2023)
- Genetic-tunneling driven energy optimizer for spin systems (2023)
- Entanglement duality in spin-spin interactions (2022)
- Tuning skyrmions in B20 compounds by 4d and 5d doping (2022)
- Macrospin model of an assembly of magnetically coupled core-shell nanoparticles (2022)
- Heat-conserving three-temperature model for ultrafast demagnetization in nickel (2022)
- Adiabatic spin dynamics and effective exchange interactions from constrained tight-binding electronic structure theory (2022)
- Magnon-magnon entanglement and its quantification via a microwave cavity (2021)
- Heisenberg and anisotropic exchange interactions in magnetic materials with correlated electronic structure and significant spin-orbit coupling (2021)
- Majority gate for two-dimensional ferromagnets lacking inversion symmetry (2021)
- Connection between magnetic interactions and the spin-wave gap of the insulating phase of NaOsO3 (2021)
- Exchange constants for local spin Hamiltonians from tight-binding models (2021)
- Hierarchy of magnon mode entanglement in antiferromagnets (2020)
- Multiscale approach for magnetization dynamics (2020)
- Nonreciprocal spin pumping damping in asymmetric magnetic trilayers (2020)
- Equation of motion and the constraining field in ab initio spin dynamics (2020)
- Multi-polaron solutions, nonlocal effects and internal modes in a nonlinear chain (2019)
- Magnetocaloric effect in Fe2P (2019)
- Peculiar magnetic states in the double perovskite Nd2NiMnO6 (2019)
- Self-organizing maps as a method for detecting phase transitions and phase identification (2019)
- Magnetic properties of Ruddlesden-Popper phases Sr3-& (2018)
- A majority gate with chiral magnetic solitons (2018)
- Investigation of the spectral properties and magnetism of BiFeO3 by dynamical mean-field theory (2018)
- Magnetic anisotropy in permalloy (2018)
- Scaling the effect of the dipolar interactions on the ZFC/FC curves of random nanoparticle assemblies (2018)
- Nonlocal Gilbert damping tensor within the torque-torque correlation model (2018)
- Heavy-mass magnetic modes in pyrochlore iridates due to dominant Dzyaloshinskii-Moriya interaction (2018)
- Magnetism and ultrafast magnetization dynamics of Co and CoMn alloys at finite temperature (2017)
- First-principles theory of electronic structure and magnetism of Cr nano-islands on Pd(111) (2017)
- Exchange interactions of CaMnO3 in the bulk and at the surface (2017)
- Theory of noncollinear interactions beyond Heisenberg exchange (2017)
- Prediction of the new efficient permanent magnet SmCoNiFe3 (2017)
- Magnetic moment of inertia within the torque-torque correlation model (2017)
- First principles studies of the Gilbert damping and exchange interactions for half-metallic Heuslers alloys (2016)
- Standard model of the rare earths analyzed from the Hubbard I approximation (2016)
- All-thermal switching of amorphous Gd-Fe alloys (2015)
- Origin of the magnetostructural coupling in FeMnP0.75Si0.25 (2014)
- Topological excitations in a kagome magnet (2014)
- The standard model of the rare-earths, analyzed from the Hubbard-Iapproximation