Laboratoire de Physique des Solides  UMR 8502
https://www.lps.upsud.fr/
frSPIP  www.spip.net Robert Style
https://www.lps.upsud.fr/spip.php?article3547
https://www.lps.upsud.fr/spip.php?article354720210218T12:37:55Ztext/htmlfrCyrille Hamon

<a href="https://www.lps.upsud.fr/spip.php?rubrique211" rel="directory">Séminaire Matière Molle</a>
 Sepideh Khodaparast
https://www.lps.upsud.fr/spip.php?article3546
https://www.lps.upsud.fr/spip.php?article354620210216T09:16:45Ztext/htmlfrCyrille Hamon

<a href="https://www.lps.upsud.fr/spip.php?rubrique211" rel="directory">Séminaire Matière Molle</a>
Resistive Switching : from microscopic models to nonequilibrium field theory
https://www.lps.upsud.fr/spip.php?article3534
https://www.lps.upsud.fr/spip.php?article353420210208T15:59:08Ztext/htmlfrMeszaros
<p>The LandauGinzburg theory is a monumental cornerstone of modern physics that unifies the various equilibrium phase transitions of matter in a common framework. The free energy, functional of the order parameter, is built on simple principles : locality, symmetry, stability, and analyticity. It is still unclear whether such a unified principlebased approach can be extended to nonequilibrium phase transitions.<br class='autobr' /> I will present the recent theoretical efforts to address the nonequilibrium (...)</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique558" rel="directory">Théorie de la Matière Condensée sur le Plateau</a>
<div class='rss_texte'><p>The LandauGinzburg theory is a monumental cornerstone of modern physics that unifies the various equilibrium phase transitions of matter in a common framework. The free energy, functional of the order parameter, is built on simple principles : locality, symmetry, stability, and analyticity. It is still unclear whether such a unified principlebased approach can be extended to nonequilibrium phase transitions.<br class='autobr' /> I will present the recent theoretical efforts to address the nonequilibrium phase transition, which occurs during the resistive switching (RS) of a variety of correlated oxides : their resistivity suddenly drops by several orders of magnitude when subject to a finite voltage bias.<br class='autobr' /> The particular case of RS will lead me to propose to abandon the principle of analyticity of the Landau potential away from thermal equilibrium. This more general question will be addressed in the simpler context of nonequilibrium versions of the Ising model. I will show how the usual φ^4 potential can be deformed by nonanalytic operators of intrinsic nonequilibrium nature and use the renormalization group to discuss their lowenergy relevance.</p></div>
Joint seminar from LPS  Etienne Fayen & Andrea Plati
https://www.lps.upsud.fr/spip.php?article3545
https://www.lps.upsud.fr/spip.php?article354520210208T15:54:55Ztext/htmlfrCyrille Hamon
<p>Etienne Fayen<br class='autobr' />Selfassembly in harddisk mixtures.<br class='autobr' />Complex phases, such as Laves phases and twodimensional dodecagonal quasicrystals, have been observed in recent selfassembly experiments of binary nanoparticle mixtures. One of the simplest way to model those experiments is to consider binary mixtures of large and small hard disks, in 2D. In the infinite pressure limit, the stability analysis of candidate phases reduces to finding the best packing structure for a given size ratio and (...)</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique211" rel="directory">Séminaire Matière Molle</a>
<div class='rss_texte'><p><strong>Etienne Fayen</strong></p> <p>Selfassembly in harddisk mixtures.</p> <p>Complex phases, such as Laves phases and twodimensional dodecagonal quasicrystals, have been observed in recent selfassembly experiments of binary nanoparticle mixtures. One of the simplest way to model those experiments is to consider binary mixtures of large and small hard disks, in 2D. In the infinite pressure limit, the stability analysis of candidate phases reduces to finding the best packing structure for a given size ratio and number ratio of the large and small disks. In this presentation, I will present infinite pressure phase diagrams of binary mixtures of (non)additive hard disks, built using candidate structures systematically generated by socalled FloppyBox Monte Carlo simulations. The resulting phase diagrams of this simple system exhibit a surprising number of different phases, including random tilings and quasicrystals, which were subsequently also found to spontaneously selfassemble in largesystem simulations.</p> <p><strong>Andrea Plati </strong></p> <p>Slow time scales and collective dynamics in dense granular matter</p> <p>A fundamental question in systems driven out of thermodynamic equilibrium is how the properties of the Non Equilibrium Stationary States (NESS) depend on the external driving. Vibrofluidized granular matter, where a NESS is reached through a balance between the energy injected by a mechanical vibration and the dissipation due to inelastic collisions, represents a good context to tackle this problem.<br class='autobr' />
In this talk i will present recent experimental and numerical results about a slow and collective dynamics that emerges in a dense vibrofluidized granular medium when the external driving is weak enough. This phenomenon is manifested in the experiments by the anomalous diffusion of a probe with an unexpected superdiffusive behavior at large times. A numerical investigation has demonstrated that the tracer's superdiffusion is related to slow rotating drifts of the granular medium. I will also discuss two complementary approaches to model this dynamics. The first one is a phenomenological model that reproduces experimental and numerical data. The second one is a lattice model of a granularlike velocity field that predicts the occurrence of slow and collective motions by the emergence of scalefree spatial correlations and typical time scales that grow with the lattice size.</p></div>
SMQ  The Nernst response of mobile superconducting vortices, Kamran Behnia
https://www.lps.upsud.fr/spip.php?article3544
https://www.lps.upsud.fr/spip.php?article354420210205T14:06:07Ztext/htmlfrMarieFrance Mariotto
<p>Any solid hosting mobile charge carriers will produce an electric field in presence of a thermal gradient. This is a consequence of the combined conservation of energy and particle number. The Nernst effect refers to the offdiagonal component of this thermoelectric response emerging in presence of a finite magnetic field.<br class='autobr' />At the beginning of the present century, it was generally assumed that the quasiparticle contribution to the Nernst signal is negligible and a BCS superconductor cannot (...)</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique553" rel="directory">Séminaire Matière Quantique (SMQ)</a>
<div class='rss_texte'><p>Any solid hosting mobile charge carriers will produce an electric field in presence of a thermal gradient. This is a consequence of the combined conservation of energy and particle number. The Nernst effect refers to the offdiagonal component of this thermoelectric response emerging in presence of a finite magnetic field.</p> <p>At the beginning of the present century, it was generally assumed that the quasiparticle contribution to the Nernst signal is negligible and a BCS superconductor cannot produce a Nernst signal far above its critical temperature. These assumptions were contradicted by subsequent experiments, which showed that the transverse thermoelectric response quantifies the amount of entropy bound to a mobile carrier of magnetic flux [1].</p> <p>A recent surprise [2] is that the entropy carried by a mobile superconducting vortex is much smaller than what it stocks in its core. Available experimental data point to the universality of the mobile sheet entropy of a magnetic flux line across different superconductors with vastly different critical temperatures. This may be due to an information barrier surrounding the topological singularity of vortices in fermionic superfluids [3].<br class='autobr' />
1. K. Behnia & H. Aubin, Rep. Prog. Phys. 79 (2016) 046502<br class='autobr' />
2. C. W. Rischau et al., Phys. Rev. Lett. 126, 077001 (2021)<br class='autobr' />
3. G. E. Volovik, The Universe in a Helium Droplet, Oxford (2003)</p></div>
SMQ  Decoding the exotic magnetismofisolatedspintriangle compound BHAPNi3, S. Chattopadhyay
https://www.lps.upsud.fr/spip.php?article3543
https://www.lps.upsud.fr/spip.php?article354320210205T13:22:00Ztext/htmlfrMarieFrance Mariotto
<p>Our newly synthesized metalorganic compound BHAPNi3 provides an excellent platform to study the magnetism of a frustrated spintriangle unit as it is comprised of antiferromagnetic spin1 triangles where each triangle is essentially magnetically isolated from the others. In this seminar, I aim to present our combined experimental and theoretical investigations that unfold presence of an exotic spin state stabilizing a robust 2/3 magnetization plateau in presence of a strong magnetic (...)</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique553" rel="directory">Séminaire Matière Quantique (SMQ)</a>
<div class='rss_texte'><p>Our newly synthesized metalorganic compound BHAPNi3 provides an excellent platform to study the magnetism of a frustrated spintriangle unit as it is comprised of antiferromagnetic spin1 triangles where each triangle is essentially magnetically isolated from the others. In this seminar, I aim to present our combined experimental and theoretical investigations that unfold presence of an exotic spin state stabilizing a robust 2/3 magnetization plateau in presence of a strong magnetic field. Low temperature acsusceptibility measurements show absence of any magnetic order/glassy state down to 60 mK. The magnetic ground state is disordered and specificheat measurements reveal the gapped nature of the spin excitations.</p></div>
SMQ  Quantum spins : from quantum phase transitions to quantum simulations,Thierry Giamarchi
https://www.lps.upsud.fr/spip.php?article3541
https://www.lps.upsud.fr/spip.php?article354120210205T11:52:00Ztext/htmlfrMarieFrance Mariotto
<p>Participer à la réunion Zoom<br class='autobr' /> https://us02web.zoom.us/j/85683947915?pwd=dW10emhyWjU5a1NiSlkrbzJyaEw2dz09<br class='autobr' />ID de réunion : 856 8394 7915<br class='autobr' /> Code secret : 406180</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique553" rel="directory">Séminaire Matière Quantique (SMQ)</a>
<div class='rss_chapo'><p>Participer à la réunion Zoom<br class='autobr' />
<a href="https://us02web.zoom.us/j/85683947915?pwd=dW10emhyWjU5a1NiSlkrbzJyaEw2dz09" class='spip_url spip_out auto' rel='nofollow external'><span class="csfoo htmla"></span>https://us02web.zoom.us/j/85683947915?pwd=dW10emhyWjU5a1NiSlkrbzJyaEw2dz09<span class="csfoo htmlb"></span></a></p> <p>ID de réunion : 856 8394 7915<br class='autobr' />
Code secret : 406180</p></div>
le calendrier de Février
https://www.lps.upsud.fr/spip.php?article3540
https://www.lps.upsud.fr/spip.php?article354020210205T11:43:08Ztext/htmlfrMarieFrance Mariotto
<p>A venir</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique553" rel="directory">Séminaire Matière Quantique (SMQ)</a>
<div class='rss_chapo'><p>A venir</p></div>
Les soutenances de thèses et habilitations à diriger les recherches (HDR)
https://www.lps.upsud.fr/spip.php?article3539
https://www.lps.upsud.fr/spip.php?article353920210204T11:20:39Ztext/htmlfrMarieFrance Mariotto
<p>Sur cette page sont répertoriées les soutenances de thèses et habilitations à diriger les recherches soutenues au LPS.</p> <p>Contact : mariefrance.mariotto@universiteparissaclay.fr</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique634" rel="directory">Chaine Youtube LPS</a>
<div class='rss_texte'><p><span style="textdecoration:underline;">Légende </span> : [TH] thèse  [HDR] habilitation à diriger les recherches</p> <p><span style="backgroundcolor:#000080;"><span style="color:#FFFFFF;">Octobre 2020</span></span><br class='autobr' />
[TH] Maxime GARNIER <a href='https:// https:/eu.bbcollab.com/recording/b02afb211d3e41cc860c85832f756406' class='spip_out' rel='external'>Les textures magnétiques pour la supraconductivité topologique</a><br class='autobr' />
[TH] Manon MARCHAND <a href="https://youtu.be/GUs6izJjBmE" class='spip_out' rel='external'>Frottement de mousses liquides sur des surfaces rugueuses</a><br class='autobr' />
<span style="backgroundcolor:#000080;"><span style="color:#FFFFFF;">Novembre 2020</span></span><br class='autobr' />
[TH] Pierre BRUNEEL <a href="https://www.youtube.com/watch?v=FCg29BIYDhA" class='spip_out' rel='external'>Propriétés électroniques et spintroniques des interfaces entre oxydes de métaux de transition</a> <br class='autobr' />
<span style="backgroundcolor:#000080;"><span style="color:#FFFFFF;">Décembre 2020</span></span> <br class='autobr' />
[TH] Raphaelle TAUB <a href="https://youtu.be/0CwAkEh3Ifo" class='spip_out' rel='external'>Assemblages d'objets élancés : mécanique et effet de contact</a><br class='autobr' />
[TH] Gianluca AIELLO <a href="https://youtu.be/PuSItqFQbkw" class='spip_out' rel='external'>Quantum dynamics of a high impedance cavity strongly coupled to Josephson junction</a><br class='autobr' />
[TH] Susana MARIN AGUILAR <a href="https://youtu.be/QipuquWUZtw" class='spip_out' rel='external'>Local structure and dynamics of dense colloidal systems : from patchy particles to hard spheres</a></p></div>
SMQ  Extreme topological response in a strongly correlated electron system, S. BuehlerPaschen
https://www.lps.upsud.fr/spip.php?article3542
https://www.lps.upsud.fr/spip.php?article354220210202T12:02:00Ztext/htmlfrMarieFrance Mariotto
<p>Tuning the correlation strength of electronic materials, to map out their phase diagrams, has led to the identification and classification of novel quantum phases, thereby elucidating the underlying physics [1]. The nature of such phase diagrams in the presence of nontrivial electronic topology represents a new frontier. After a general discussion of this background I will introduce a new state of matter, the WeylKondo semimetal, discovered in a joint experimental [2,3] and theoretical (...)</p>

<a href="https://www.lps.upsud.fr/spip.php?rubrique553" rel="directory">Séminaire Matière Quantique (SMQ)</a>
<div class='rss_texte'><p>Tuning the correlation strength of electronic materials, to map out their phase diagrams, has led to the identification and classification of novel quantum phases, thereby elucidating the underlying physics [1]. The nature of such phase diagrams in the presence of nontrivial electronic topology represents a new frontier. After a general discussion of this background I will introduce a new state of matter, the WeylKondo semimetal, discovered in a joint experimental [2,3] and theoretical [4,5] effort. I will present experiments on the heavy fermion material Ce3Bi4Pd3 [2], a semimetallic cousin of the wellknown Kondo insulator Ce3Bi4Pt3. The strong spinorbit coupling of the constituting elements together with the noncentrosymmetric and nonsymmorphic structure make this material a promising candidate to realize this new state. Indeed, our thermodynamic [2] and electrical transport [3] measurements evidence a highly unusual ``extreme topological response'', which can be rationalized within the WeylKondo semimetal picture [25]. I will furthermore show how this new state of matter transforms under the action of magnetic field [6], and close by highlighting the potential of such tuning studies for future discovery [7].</p> <p>[1] S. Paschen and Q. Si, Quantum phases driven by strong correlations, Nat. Rev. Phys. 3, 9 (2021).<br class='autobr' />
[2] S. Dzsaber, L. Prochaska, A. Sidorenko, G. Eguchi, R. Svagera, M. Waas, A. Prokofiev, Q. Si, and S. Paschen, Kondo insulator to semimetal transformation tuned by spinorbit coupling, Phys. Rev. Lett. 118, 246601 (2017).<br class='autobr' />
[3] S. Dzsaber, X. Yan, M. Taupin, G. Eguchi, A. Prokofiev, T. Shiroka, P. Blaha, O. Rubel, S.E. Grefe, H.H. Lai, Q. Si, and S. Paschen, Giant spontaneous Hall effect in a nonmagnetic WeylKondo semimetal, PNAS 118, e2013386118 (2021).<br class='autobr' />
[4] H.H. Lai, S.E. Grefe, S. Paschen, and Q. Si, Weyl–Kondo semimetal in heavyfermion systems, PNAS 115, 93 (2018).<br class='autobr' />
[5] S.E. Grefe, H.H. Lai, S. Paschen, and Q. Si, WeylKondo semimetals in nonsymmorphic systems, Phys. Rev. B 101, 075138 (2020). <br class='autobr' />
[6] S. Dzsaber, D.A. Zocco, A. McCollam, F. Weickert, R. McDonald, M. Taupin, X. Yan, A. Prokofiev, L.M.K. Tang, B. Vlaar, L. Stritzinger, M. Jaime, Q. Si, and S. Paschen, Quenching a WeylKondo semimetal by magnetic field, arXiv:1906.01182.<br class='autobr' />
[7] W. T. Fuhrman, A. Sidorenko, J. Hänel, H. Winkler, A. Prokofiev, J. A. RodriguezRivera, Y. Qiu, P. Blaha, Q. Si, C. L. Broholm, and S. Paschen, Pristine quantum criticality in a Kondo semimetal, arXiv:2007.09460</p></div>