Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study
We perform a microscopic study of itinerant ferromagnetic systems. We reveal a very rich phase diagram in the three-dimensional space spanned by the chemical potential, a magnetic field, and temperature beyond the Landau theory analyzed so far. Besides a generic wing structure near a tricritical poi...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/acc04d |
| _version_ | 1797748689555423232 |
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| author | Hiroyuki Yamase |
| author_facet | Hiroyuki Yamase |
| author_sort | Hiroyuki Yamase |
| collection | DOAJ |
| description | We perform a microscopic study of itinerant ferromagnetic systems. We reveal a very rich phase diagram in the three-dimensional space spanned by the chemical potential, a magnetic field, and temperature beyond the Landau theory analyzed so far. Besides a generic wing structure near a tricritical point upon introducing the magnetic field, we find that an additional wing can be generated close to a quantum critical end point (QCEP) and also even from deeply inside the ferromagnetic phase. A tilting of the wing controls the entropy jump associated with the metamagnetic transition. Ferromagnetic and metamagnetic transitions are usually accompanied by a Lifshitz transition at low temperatures, i.e. a change of Fermi surface topology including the disappearance of the Fermi surface. In particular, the Fermi surface of either spin band vanishes at the QCEP. These rich phase diagrams are understood in terms of the density of states and the breaking of particle-hole symmetry in the presence of a next nearest-neighbor-hopping integral t ʹ, which is expected in actual materials. The obtained phase diagrams are discussed in a possible connection to itinerant ferromagnetic systems such as UGe _2 , UCoAl, ZrZn _2 , and others including materials exhibiting the magnetocaloric effect. |
| first_indexed | 2024-03-12T16:08:25Z |
| format | Article |
| id | doaj.art-5acd312a46ab4a11a3d961123d85d51f |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:08:25Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-5acd312a46ab4a11a3d961123d85d51f2023-08-09T14:13:39ZengIOP PublishingNew Journal of Physics1367-26302023-01-0125303300410.1088/1367-2630/acc04dFerromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic studyHiroyuki Yamase0International Center of Materials Nanoarchitectonics, National Institute for Materials Science , Tsukuba 305-0047, JapanWe perform a microscopic study of itinerant ferromagnetic systems. We reveal a very rich phase diagram in the three-dimensional space spanned by the chemical potential, a magnetic field, and temperature beyond the Landau theory analyzed so far. Besides a generic wing structure near a tricritical point upon introducing the magnetic field, we find that an additional wing can be generated close to a quantum critical end point (QCEP) and also even from deeply inside the ferromagnetic phase. A tilting of the wing controls the entropy jump associated with the metamagnetic transition. Ferromagnetic and metamagnetic transitions are usually accompanied by a Lifshitz transition at low temperatures, i.e. a change of Fermi surface topology including the disappearance of the Fermi surface. In particular, the Fermi surface of either spin band vanishes at the QCEP. These rich phase diagrams are understood in terms of the density of states and the breaking of particle-hole symmetry in the presence of a next nearest-neighbor-hopping integral t ʹ, which is expected in actual materials. The obtained phase diagrams are discussed in a possible connection to itinerant ferromagnetic systems such as UGe _2 , UCoAl, ZrZn _2 , and others including materials exhibiting the magnetocaloric effect.https://doi.org/10.1088/1367-2630/acc04ditinerant metamagnetismitinerant ferromagnetismphase diagramdensity of states |
| spellingShingle | Hiroyuki Yamase Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study New Journal of Physics itinerant metamagnetism itinerant ferromagnetism phase diagram density of states |
| title | Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study |
| title_full | Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study |
| title_fullStr | Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study |
| title_full_unstemmed | Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study |
| title_short | Ferromagnetic and metamagnetic transitions in itinerant electron systems: a microscopic study |
| title_sort | ferromagnetic and metamagnetic transitions in itinerant electron systems a microscopic study |
| topic | itinerant metamagnetism itinerant ferromagnetism phase diagram density of states |
| url | https://doi.org/10.1088/1367-2630/acc04d |
| work_keys_str_mv | AT hiroyukiyamase ferromagneticandmetamagnetictransitionsinitinerantelectronsystemsamicroscopicstudy |