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Emmanouil Markoulakis

Publications and source records attributed to Emmanouil Markoulakis.

6 recordsLinked to original sources
arXiv2025

Ferromagnetic Phase Transition of DPPH Induced by a Helical Magnetic Field

We report the results and unique instrument configuration of a novel experiment in which we successfully transitioned a DPPH sample from its natural paramagnetic state and essentially a non-magnetic material to a ferromagnetic state at room temperature. This was achieved using a specifically applied helical flux magnetic field. The DPPH sample (2,2-diphenyl-1-picrylhydrazyl) remained ferromagnetic for at least one hour after the experiment, indicating that a transformation in the material was induced by the external field rather than being merely a temporary magnetic phase transition observed only during the experiment. The external magnetic field used had a helical pitch angle of approximately $54.7{\deg}$, known mathematically as the Magic Angle, relative to the +z-axis, which is aligned with the normal S to N external field's magnetic moment vector. Based on the phenomenology of the experiment and results, we suggest that this specific magic angle corresponding to the known quantization precession spin angle of free electrons under a homogeneous straight flux magnetic field potentially enhances the percentage of unpaired valence electrons within the DPPH material, allowing them to align in parallel with the applied external field. Typically, in paramagnetic materials, the distribution of unpaired electrons' quantum spins relative to an external field is nearly random, showing roughly a 50% chance of either parallel or antiparallel alignment. Only a slight majority preference exists in one alignment direction due to the Boltzmann thermal distribution, which contributes to the paramagnetic nature of these materials. In our measurements, we found that the induced ferromagnetism of the DPPH sample resulted in an abnormal thousand-fold decimal value increase in relative magnetic permeability at ${\mu}{\approx}1.4$, compared to its typical paramagnetic value of $1.0001$ for this material.

cond-mat.mtrl-sci↗
arXiv2021

Real time display with the ferrolens of homogeneous magnetic fields

In our previous published research we have studied the applications of the ferrolens for the observation and qualitative analysis of non-homogeneous magnetic fields. Latest developments over the last few years of the ferrolens increased multifold the sensitivity of this device allowing it to display magnetic fields as low as 10mT in strength and therefore it is possible now to observe also the homogeneous (i.e. straight parallel magnetic flux lines of uniform density in space) magnetic field existing inside air solenoids and between N-S poles of two attracting separated permanent magnets. We present and analyze herein these novel observations of homogeneous magnetic fields with the ferrolens and as a potential new application of this device. The ferrolens can now display the projected magnetic field on air from a distance without needing to be in physical contact with the field source. Experiments were carried out to demonstrate these new capabilities of the ferrolens as a nanomagnetic flux viewer, real-time physical device and scientific qualitative tool. We compare the geometry of magnetic fields of condensed matter ferromagnets with that of magnetic fields inside electrical air solenoids. Specifically, the homogeneous field between two N-S attracting magnets at a distance as well as inside air solenoids and Helmholtz coils and also the non-homogeneous total field of single dipole permanent magnets were observed using a latest generation very sensitive ferrolens. The unique feature of this magneto optic fluid thin film physical device is that it can display discrete magnetic flux lines of the macroscopic field. Also we show how the ferrolens can be used to detect qualitatively the symmetry center of a non ideal homogeneous magnetic field.

physics.app-ph↗
arXiv2020

A Synthetic Macroscopic Magnetic Unipole

We demonstrate experimentally with a prototype for the first time, that an artificial emergent magnetic unipole hedgehog field in a simply connected three dimensional domain is possible, emulating effectively the Dirac model by simply using a novel permanent magnets' topology and geometrical arrangement in a ring array. Although similar effects were demonstrated by others over the last decade, with these effects usually observed and lasting for a small fraction in time and applied at the quantum or microscopic scale using primary BECs, Skyrmions, Spin Ice and recently Chiral Magnets this was never shown until now and performed at the macro scale and by using normal magnets. The synthetic magnetic unipole ring array prototype progressively twists and steers the magnetic flux into vanishing curl field (i.e. vortex) geometry towards the center of the ring and its air cap. This mere act alone proves enough to create the desired effect and an apparent isolated magnetic unipole region is observed at the center of this magnetic ring array, as we have mapped with a three axis magnetometer and show with the quantum magnetic-optic device flux viewer, the ferrolens. This magnetic unipole is stable at room temperature. Because its macroscopic nature we were able to record for the first time the unique signal signature patterns of magnetic monopoles synthetic or natural, passing through a non-ideal ohmic solenoid shown in Fig.17 which can be used by researches to aid them in the detection of magnetic monopoles.

physics.ins-det↗
arXiv2019

Real time observation of a stationary magneton

The magnetic dipole field geometry of subatomic elementary particles like the electron differs from the classical macroscopic field imprint of a bar magnet. It resembles more like an eight figure or else joint double quantum-dots instead of the classical, spherical more uniform field of a bar magnet. This actual subatomic quantum magnetic field of an electron at rest, is called Quantum Magnet or else a Magneton. Normally, a macroscale bar magnet should behave like a relative giant Quantum Magnet with identical magnetic dipole field imprint since all of its individual magnetons collectively inside the material, dipole moments are uniformly aligned forming the total net field of the magnet. However due to Quantum Decoherence (QDE) phenomenon at the macroscale and macroscopic magnetic field imaging sensors limitations which cannot pickup these rapid quantum magnetization fluctuations, this field is masked and not visible at the macroscale. By using the relative inexpensive submicron resolution Ferrolens quantum magnetic optical sensor and method, we can actually make this net magneton field visible on macroscale magnets. We call this net total field herein, Quantum Field of Magnet (QFM) differentiating it therefore from the field of the single subatomic magneton thus quantum magnet. Additionally, the unique potential of the Ferrolens device to display also the magnetic flux lines of this macroscopically projected giant Magenton gives us the unique opportunity to study the individual magnetic flux lines geometrical pattern that of a single subatomic magneton. We describe this particular magnetic flux of the magneton observed, quantum magnetic flux. Therefore a novel observation has been made that the QFM of the Magnet-Magneton consists of a dipole vortex shaped magnetic flux geometrical pattern responsible for creating the classical macroscopic N-S field of the magnet.

quant-ph↗
arXiv2018

The Quantum Field Of A Magnet Shown By A Nanomagnetic Ferrolens

It has been more than two hundred years since the first iron filings experiment, showing us the 2D macroscopic magnetic imprint of the field of a permanent magnet. However, latest developments in modern nanomagnetic passive direct observation devices reveal in real-time and color a more intriguing 3D dynamic and detailed image of the field of a magnet, with surprising new findings, that can change our perspective for dipole magnetism forever and lead to new research. This research is a continuation of our previous work (DOI: 10.1016/j.jmmm.2017.12.023). The magnetostatic fields were under our scope and examined with the aid of the ferrolens. We are presenting experimental and photographical evidence, demonstrating the true complex 3D Euclidian geometry of the quantum field of permanent magnets that have never been seen before and the classic iron filings experiment, apart of its 2D limitations, fails to depict. An analysis of why and what these iron filings inherent limitations are, giving us an incomplete and also in some degree misguiding image of the magnetic field of a magnet is carried out, whereas, as we prove the ferrolens is free of these limitations and its far more advanced visualization capabilities is allowing it to show the quantum image with depth of field information, of the dipole field of a permanent magnet. For the first time the domain wall (i.e. Bloch or Neel wall) region of the field of a magnet is clearly made visible by the ferrolens along with what phenomenon is actually taking place there, leading to the inescapable conclusion, novel observation and experimental evidence that the field of any dipole magnet actually consists of two distinct and separate toroidal shaped 3D magnetic bubbles, each located at either side of the dipole around the exact spatial regions where the two poles of the magnet reside.

physics.app-ph↗