Possible quantum nematic phase in a colossal magnetoresistance material

The arrangement of nanoscale building blocks into patterns with microscale periodicity is challenging to achieve via self-assembly processes. Here, we report on the phase transition-driven collective assembly of gold nanoparticles in a thermotropic liquid crystal. A temperature-induced transition from the isotropic to the nematic phase leads to the assembly of individual nanometre-sized particles into arrays of micrometre-sized aggregates, whose size and characteristic spacing can be tuned by varying the cooling rate. This fully reversible process offers hierarchical control over structural order on the molecular, nanoscopic, and microscopic level and is an interesting model system for the programmable patterning of nanocomposites with access to micrometre-sized periodicities.

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Polar and nonpolar orderings in the electrically induced isotropic-nematic phase transition

Physical Review E ◽

10.1103/physreve.78.040702 ◽

2008 ◽

Vol 78 (4) ◽

Cited By ~ 5

Author(s):

Mingxia Gu ◽

Sergij V. Shiyanovskii ◽

Oleg D. Lavrentovich

Keyword(s):

Phase Transition ◽

Nematic Phase

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Pressure-tuned colossal magnetoresistance effect in n-type CdCr2Se4

Applied Physics Letters ◽

10.1063/5.0049868 ◽

2021 ◽

Vol 118 (26) ◽

pp. 262407

Author(s):

Bowen Zhang ◽

Chuanchuan Gu ◽

Chao An ◽

Xuliang Chen ◽

Yonghui Zhou ◽

...

Keyword(s):

Colossal Magnetoresistance ◽

Magnetoresistance Effect ◽

Colossal Magnetoresistance Effect

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Effect of the surfactant head-group size dependence of the dye-surfactant interactions on the lyotropic uniaxial to biaxial nematic phase transitions

Journal of Molecular Liquids ◽

10.1016/j.molliq.2021.115842 ◽

2021 ◽

pp. 115842

Author(s):

Erol Akpinar ◽

Nazli Uygur ◽

Oznur Demir Ordu ◽

Dennys Reis ◽

Antônio Martins Figueiredo Neto

Keyword(s):

Phase Transitions ◽

Group Size ◽

Nematic Phase ◽

Size Dependence ◽

Head Group ◽

Surfactant Interactions ◽

Biaxial Nematic ◽

Biaxial Nematic Phase

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From Bend to Splay Dominated Elasticity in Nematics

Crystals ◽

10.3390/cryst11070831 ◽

2021 ◽

Vol 11 (7) ◽

pp. 831

Author(s):

Davide Revignas ◽

Alberta Ferrarini

Keyword(s):

Liquid Crystal ◽

Nematic Phase ◽

Low Cost ◽

Elastic Behavior ◽

Computational Investigation ◽

Apical Angle ◽

Polar Order ◽

The Past ◽

Bend Angles ◽

Analogous Effect

In the past decade, much evidence has been provided for an unusually low cost for bend deformations in the nematic phase of bent-core mesogens and bimesogens (liquid crystal dimers) having a bent shape on average. Recently, an analogous effect was observed for the splay mode of bent-core mesogens with an acute apical angle. Here, we present a systematic computational investigation of the Frank elastic constants of nematics made of V-shaped particles, with bend angles ranging from acute to obtuse. We show that by tuning this angle, the elastic behavior switches from bend dominated (K33>K11) to splay dominated (K11>K33), with anomalously low values of the splay and the bend constant, respectively. This is related to a change in the shape polarity of particles, which is associated with the emergence of polar order, longitudinal for splay and transversal for bend deformations. Crucial to this study is the use of a recently developed microscopic elastic theory, able to account for the interplay of mesogen morphology and director deformations.

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Topological nematic phase transition in Kitaev magnets under applied magnetic fields

Physical Review Research ◽

10.1103/physrevresearch.3.023189 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Masahiro O. Takahashi ◽

Masahiko G. Yamada ◽

Daichi Takikawa ◽

Takeshi Mizushima ◽

Satoshi Fujimoto

Keyword(s):

Phase Transition ◽

Magnetic Fields ◽

Nematic Phase

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Ultrafast dynamical Lifshitz transition

Science Advances ◽

10.1126/sciadv.abd9275 ◽

2021 ◽

Vol 7 (17) ◽

pp. eabd9275

Author(s):

Samuel Beaulieu ◽

Shuo Dong ◽

Nicolas Tancogne-Dejean ◽

Maciej Dendzik ◽

Tommaso Pincelli ◽

...

Keyword(s):

Fermi Surface ◽

Colossal Magnetoresistance ◽

Surface Topology ◽

Strongly Correlated ◽

Many Body ◽

Time Resolved ◽

Weyl Semimetal ◽

Lifshitz Transition ◽

Fermi Surface Topology ◽

Many Body Systems

Fermi surface is at the heart of our understanding of metals and strongly correlated many-body systems. An abrupt change in the Fermi surface topology, also called Lifshitz transition, can lead to the emergence of fascinating phenomena like colossal magnetoresistance and superconductivity. While Lifshitz transitions have been demonstrated for a broad range of materials by equilibrium tuning of macroscopic parameters such as strain, doping, pressure, and temperature, a nonequilibrium dynamical route toward ultrafast modification of the Fermi surface topology has not been experimentally demonstrated. Combining time-resolved multidimensional photoemission spectroscopy with state-of-the-art TDDFT+U simulations, we introduce a scheme for driving an ultrafast Lifshitz transition in the correlated type-II Weyl semimetal Td-MoTe2. We demonstrate that this nonequilibrium topological electronic transition finds its microscopic origin in the dynamical modification of the effective electronic correlations. These results shed light on a previously unexplored ultrafast scheme for controlling the Fermi surface topology in correlated quantum materials.

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