###### Home

Hi !

I’m Ludovic, a CNRS researcher. I work in the Condensed Matter Theory group of the LOMA in Bordeaux. Before joining CNRS, I worked in Okinawa (Japan), Oxford (UK), Dresden (Germany) and Lyon (France).

We are interested in what happens when electrons are not happy to live together in a crystal. More precisely, in some materials, all interactions between spins cannot be satisfied at the same time. This leads to what is called magnetic frustration and strongly hinders the system to order on long length scales. In our everyday life, it would be the same as if a cup of water would never freeze, even in the middle of Antarctica !

For scientists, frustration has opened a window to explore some of the hidden properties of matter at very low temperatures, which is where quantum mechanics rules. We spend most of our time looking through this window, trying to make sense of what we see. The absence of order often leads to persistent fluctuations, paradoxically coupled to strong magnetic correlations. These phases, called « spin liquids », can often be described rather beautifully by emergent gauge field theories, making contact with a physics usually attached to high energy. In this field, we are especially interested in emergent phenomena (quasi-particles, extended fractal structures …), topological phases, exotic phase transitions and out-of-equilibrium dynamics, to cite but a few. Our research often sits at the frontier between Condensed Matter and Statistical Physics.

Photo by Letizia Diamante, OIST / CC BY 2.0

If you want to know more, please find below a few articles written by science journalists who have done a great job explaining our research:

- “A Magnet From the Bizarro World” by Yuen Yiu (Inside Science, 2017)
- “Spin Liquid on a peak” by Greta Keenan (OIST, 2016)
- “The Quest for Spin Liquids” by Rebecca Hofland (OIST, 2016)
- “Magnetic Monopoles: Crystal Clear” by Letizia Diamante (OIST, 2015)
- “
*Premiers monopôles magnétiques*” by Franck Daninos (La Recherche, 2010), in french - “Hunting the mysterious monopole” by Eugenie Reich (New Scientist, 2009)
- “Trolling for poles” (Nature Research Highlights, 2009)

###### Team

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Hi there, I’m Tristan. I’m a PhD student at Institut Néel in Grenoble (France), where I work under the supervision of Arnaud Ralko (Institut Néel), co-supervised by Ludovic in Bordeaux.

I’m most interested in the unconventional phases of matter arising in frustrated systems. I really enjoy discovering all about those new phases of matter, such as quantum spin liquids, and studying their topological properties using a variety of numerical methods and models. I also teach at the University of Grenoble which has been since the beginning a wonderful and stimulating experience.

I love being in Grenoble, the city is surrounded by mountains which makes it easy to wander around and go skiing. I also spend my spare time playing music with my friends, cooking cookies and other sweet stuff, enjoying good movies and taking it easy : )

#### Alumni

**PhD student**

**Afterwards, they moved to …**

co-supervised with N. Shannon

with M. Imada

**Postdoc**

**Afterwards, they moved to …**

with L. Messio

**Interns (3-4 months)**

**Afterwards, they moved to …**

in Grenoble)

co-supervised with A. Ralko

co-supervised with me

co-supervised with K. Essafi

G. Stephens

co-supervised with N. Shannon

H. Sugawara

###### CV

#### Employment history

since 2017: CNRS researcher at the LOMA, University of Bordeaux, France

2013 – 2016: Group leader at the Okinawa Institute of Science & Techonology (OIST), Japan

2012 – 2012: Postdoc at OIST, Okinawa, Japan

2009 – 2011: Postdoc at the Max Planck Institute (PkS), Dresden, Germany

2006 – 2009: Ph.D student and teaching assistant at the Ecole Normale Supérieure of Lyon, France

2002 – 2006: Normalien of the ENS Lyon, France (civil servant contract)

#### Visiting positions

2017 – onwards: OIST, Okinawa, Japan (regular visits)

2015: Ecole Normale Supérieure of Lyon, France (Guest professor, 1 month)

2012: University of Oxford, UK (8 months)

2010: University of Waterloo, Canada (1.5 months)

2009: University of Waterloo, Canada (1 month)

2007: University of Oxford, UK (4 months)

2006: University of Campinas, Brazil (1 month)

2006: University Pierre & Marie Curie, Paris, France (4 months, intern)

2004: University of Campinas, Brazil (3 months, intern)

#### Teaching

Lab works in Electronics and Thermodynamic (Master) at the ENS Lyon (2006 – 2009)

Tutorials in Quantum Mechanics (Licence) at the ENS Lyon (2007, 2008)

Master Degree in Education (*Agrégation*, 2005)

#### Honours & Fundings

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2019 – 2022 (4 years): Principal Investigator of the project

*Designing frustration: surface effects and disorder*

funded by the French National Research Agency (ANR).

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2014 – 2017 (3 years): Principal Investigator of the project

*Lattice and Charge Engineering of Spin Ice*

funded by the Japan Society for the Promotion of Science (*Kakenhi*, JSPS),

in collaboration with Masafumi Udagawa from Gakushuin University in Tokyo.

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Our work on Signature of magnetic monopole and Dirac string dynamics in spin ice

is one of the 12 featured articles for the 10-year anniversary of Nature Physics.

###### Publications

You can find my publication details on Google Scholar

List of my publications on Hal Archive

### Preprints

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30. arXiv:1902.10934

H. Yan, O. Benton, L.D.C. Jaubert & N. Shannon

Rank-2 U(1) spin liquid on the breathing pyrochlore lattice

### Publications

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29. Physical Review B **98**, 144446 (2018) [arXiv]

T. Mizoguchi, L.D.C. Jaubert, R. Moessner & M. Udagawa

Magnetic clustering, half-moons, and shadow pinch points as signals of a proximate Coulomb phase in frustrated Heisenberg magnets

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28. Physical Review Letters **121**, 067201 (2018) [arxiv]

Owen Benton, L.D.C. Jaubert, Rajiv Singh, Jaan Oitmaa, Nic Shannon

Quantum Spin Ice with Frustrated Transverse Exchange: From a π-Flux Phase to a Nematic Quantum Spin Liquid

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27. Physical Review X **7**, 041057 (2017) [arxiv]

M. Taillefumier, O. Benton, H. Yan, L.D.C. Jaubert, N. Shannon

Competing spin liquids and hidden spin-nematic order in spin ice with frustrated transverse exchange

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26. Physical Review B **96**, 205126 (2017) [arxiv]

Karim Essafi, Owen Benton, L.D.C. Jaubert

Generic nearest-neighbor kagome model: XYZ and Dzyaloshinskii-Moriya couplings with comparison to the pyrochlore-lattice case

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25. Physical Review Letters **119**, 077207 (2017) [arxiv]

T. Mizoguchi, L.D.C. Jaubert & M. Udagawa

Clustering of Topological Charges in a Kagome Classical Spin Liquid

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24. Journal of Physics: Condensed Matter **29**, 315802 (2017) [arxiv]

K. Essafi, L.D.C. Jaubert & M. Udagawa

Flat bands and Dirac cones in breathing lattices

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23. Physical Review Letters **118**, 207206 (2017) [arxiv]

L.D.C. Jaubert , T. Lin, T.S. Opel, P.C.W. Holdsworth & M.J.P. Gingras

Spin Ice Thin Film: Surface Ordering, Emergent Square Ice and Strain Effects

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22. Physical Review B **95**, 094422 (2017) [arxiv]

H. Yan , O. Benton, L.D.C. Jaubert & N. Shannon

Theory of multiple-phase competition in pyrochlore magnets with anisotropic exchange, with application to Yb2Ti2O7, Er2Ti2O7 and Er2Sn2O7

#@Gilead## “Highly cited paper” (top 1% most cited in the field and year, Web of Science)

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21. Physical Review B **94**, 224413 (2016) [arxiv]

D.T. Liu, F.J. Burnell, L.D.C. Jaubert & J.T. Chalker

Classical spin liquids in stacked triangular lattice Ising antiferromagnets

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20. Physical Review B **94**, 104416 (2016) [arxiv]

M. Udagawa, L.D.C. Jaubert, C. Castelnovo & R. Moessner

Out-of-equilibrium dynamics and extended textures of topological defects in spin ice

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19. Physical Review B **94**, 014429 (2016) [arxiv]

R. Pohle, O. Benton, & L.D.C. Jaubert

Reentrance of disorder in the anisotropic shuriken Ising model

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18. Nature Communications **7**, 11572 (2016) [arxiv]

O. Benton, L.D.C. Jaubert, H. Yan & N. Shannon

A spin-liquid with pinch-line singularities on the pyrochlore lattice

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17. Nature Communications **7**, 10297 (2016) [arxiv]

K. Essafi, O. Benton, L.D.C. Jaubert

A Kagome Map of Spin Liquids from XXZ to Dzyaloshinskii-Moriya Ferromagnet

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16. Physical Review Letters **115**, 267208 (2015) [arxiv]

L.D.C. Jaubert, O. Benton, J.G. Rau, J. Oitmaa, R.R.P. Singh, N. Shannon & M.J.P. Gingras

Are mulitphase competition & order-by-disorder the keys to understanding Yb2Ti2O7 ?

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15. Spin **5**, 1540005 (2015) [arxiv]

L.D.C. Jaubert

Monopole holes in a Partially Ordered Spin Liquid

# invited paper for the special issue on “Quantum Spin Ice and Liquid in Geometrically Frustrated Magnets”

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14. Physical Review B **91**, 214422 (2015) [arxiv]

L.D.C. Jaubert & R. Moessner

Multiferroicity in spin ice: Towards magnetic crystallography of Tb2Ti2O7 in a field

# PRB Editor’s suggestion

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13. Physical Review X **4**, 011007 (2014) [arxiv]

M. Brooks-Bartlett, S.T. Banks, L.D.C. Jaubert, A. Harman-Clarke & P.C.W. Holdsworth

Magnetic Moment Fragmentation and Monopole Crystallization

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12. Journal of Physics: Condensed Matter **25**, 386002 (2013) [arxiv]

L. Bovo, L.D.C. Jaubert, P.C.W. Holdsworth & S.T. Bramwell

Crystal Shape-Dependent Magnetic Susceptibility and Curie Law Crossover in the Spin Ices Dy2Ti2O7 and Ho2Ti2O7

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11. Physical Review X **3**, 011014 (2013) [arxiv]

L.D.C. Jaubert, M.J. Harris, T. Fennell, R.G. Melko, S.T. Bramwell & P.C.W. Holdsworth

Topological Sector Fluctuations and Curie Law Crossover in Spin Ice

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10. Physical Review B **85**, 054425 (2012) [arxiv]

L.D.C. Jaubert, S. Piatecki, M. Haque & R. Moessner

Itinerant electrons in the Coulomb phase

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9. Physical Review Letters **107**, 177202 (2011) [arxiv]

L.D.C. Jaubert, M. Haque & R. Moessner

Analysis of a fully packed loop model arising in a magnetic Coulomb phase

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8. Journal of Physics: Condensed Matter **23**, 164222 (2011) [arxiv]

L.D.C. Jaubert & P.C.W. Holdsworth

Magnetic Monopole Dynamics in Spin Ice

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7. Physical Review Letters **105**, 087201 (2010) [arxiv]

L.D.C. Jaubert, J.T. Chalker, P.C.W. Holdsworth & R. Moessner

Spin ice under pressure: symmetry enhancement and infinite order multicriticality

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6. Nature Physics **5**, 258-261 (2009) [arxiv]

L.D.C. Jaubert & P.C.W. Holdsworth

Signature of magnetic monopole and Dirac string dynamics in spin ice

# “Highly cited paper” (top 1% most cited in the field and year, Web of Science)

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5. Journal of Physics: Conference Series **145**, 012024 (2009) [arxiv]

L.D.C. Jaubert, J.T. Chalker, P.C.W. Holdsworth & R. Moessner

A three dimensional Kasteleyn transition in spin ice

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4. Physics Review Letters **100**, 067207 (2008) [arxiv]

L.D.C. Jaubert, J.T. Chalker, P.C.W. Holdsworth & R. Moessner

Three-Dimensional Kasteleyn Transition: Spin Ice in a [100] Field

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3. Journal of Statistical Mechanics P05001 (2007) [arxiv]

L.D.C. Jaubert, C. Chamon, L.F. Cugliandolo & M. Picco

Growing dynamical length, scaling and heterogeneities in the 3d Edwards-Anderson model

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2. Physica Scripta **75**, 363-373 (2007) [arxiv]

L.D.C. Jaubert & M.A.M. de Aguiar

Semiclassical tunnelling of wavepackets with real trajectories

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1. Journal of Physics A **38**, 4645-4664 (2005) [arxiv]

M.A.M. de Aguiar, M. Baranger, L. Jaubert, F. Parisio & A.D. Ribeiro

Semiclassical propagation of wavepackets with complex and real trajectories

### Ph.D. thesis

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Ecole Normale Supérieure de Lyon

Topological Constraints and Defects in Spin Ice

###### Talks & Events

#### Forthcoming

Nov. 2019|Santa Barbara

Oct. 2019 | Daejeon

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Jun. 2019 | Lorraine

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May 2019 | Bordeaux

Apr. 2019 | Munich

#### Organised events – Thank you for coming !

Aug. 2018 | Grenoble

« Emergent Phenomena in Frustrated Magnetism » at the bi-annual conference of the French Physical Society

*Journée de la Matière Condensée*

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Apr. 2018 | Orsay

French Pyrochlore Magnets meeting (

*Laboratoire de Physique des Solides*)

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#### Invited talks

Mar. 2019| Boston

Talk: Neutron scattering signatures of pyrochlore spin liquids and nematic phases.

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Nov. 2018 | Dresden

Talk: Reentrant behaviour in spin liquids and half-moon patterns in neutron scattering.

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Oct. 2018 | Pohang

Place: Asia Pacific Center for Theoretical Physics

Talk: Reentrant behaviour in spin liquids

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Jun. 2018 | Zurich

Place: University of Zurich

Talk: Reentrant behaviour in spin liquids

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Aug. 2017 | Daejeon

Place: Institute for Basic Science – Center for Theoretical Physics of Complex Systems

Talk: Emergent gauge theories on pyrochlore

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Jul. 2017 | Grenoble

Place:

*Centre de Physique Théorique de Grenoble-Alpes*

Talk: Anisotropic models on the kagome lattice.

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Jun. 2017 | Waterloo

Place: Perimeter Institute

Talk: Multi-phase competition in Yb

_{2}Ti

_{2}O

_{7}and monopole crystal in Tb

_{2}Ti

_{2}O

_{7}.

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Dec. 2016 | Kolkata

Place: University of Calcutta, Saha Institute of Nuclear Physics

Talk: Fragmented spin liquids.

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Aug. 2015 | Kyoto

Place: Yukawa Institute for Theoretical Physics of the University of Kyoto

Talk: Non-equilibrium physics in spin ice.

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May. 2014 | Okinawa

Place: Okinawa Institute of Science and Technology

Talk: Exotic phases in rare-earth pyrochlore oxides.

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Feb. 2012 | Warwick

Place: University of Warwick

Talk: « Dual electrolytes » in spin-ice simulations.

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Dec. 2011 | Natal

Place: International Institute of Physics

Talk: Loop models in the Coulomb phase coupled to itinerant electrons.

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Oct. 2010 | London

Place: Royal Holloway University of London

Talk: Monopole dynamics and monopole liquids.

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Apr. 2010 | Dresden

Place: Max Planck Institute – Physics for Complex Systems

Talk: Monopole dynamics and topological phase transitions.

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Mar. 2010 | Portland

#### Seminars

Jan. 2019 | Wako

Dec. 2018 | Kyoto

Talk: Neutron scattering signatures of spin liquids.

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Dec. 2018 | Nagoya

Sep. 2017 | Okinawa

Jul. 2017 | Osaka

Jun. 2017 | Waterloo

Apr. 2017 | Cambridge

Apr. 2017 | Toulouse

Apr. 2017 | Daejeon

Talk: Fragmented spin liquids.

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Dec. 2016 | Bangalore

Jul. 2016 | Tainan

Dec. 2015 | Lyon

Dec. 2015 | Nancy

Nov. 2015 | Grenoble

Nov. 2015 | Paris

Mar. 2014 | Paris

Mar. 2014 | Tokyo

Dec. 2013 | Grenoble

Nov. 2013 | Lyon

Nov. 2013 | Lausanne

Nov. 2013 | Paris

Jun. 2013 | Cambridge

Jun. 2013 | London

Mar. 2013 | Yale

Mar. 2013 | Tokyo

Mar. 2013 | Tokyo

May 2012 | Oxfordshire

Mar. 2012 | Paris

Feb. 2012 | Yale

Feb. 2012 | London

Talk: Loop models in the Coulomb phase coupled to itinerant electrons.

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Feb. 2012 | Oxford

Oct. 2011 | Toulouse

Oct. 2011 | Paris

Feb. 2011 | Grenoble

Feb. 2011 | Saclay

Jan. 2011 | Wurzburg

Oct. 2010 | Toulouse

Oct. 2010 | Orsay

Jul. 2010 | Cologne

Talk: Monopole dynamics and topological phase transitions.

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Apr. 2010 | Hamilton

Feb. 2009 | Waterloo

Feb. 2009 | Orsay

Nov. 2008 | Dresden

Talk: Topological phase transitions.

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#### Contributed talks

Jul. 2018 | Davis

Mar. 2017 | Bordeaux

*Matériaux Etats ElecTronIques Interactions et Couplages non Conventionnels*(GdR MEETICC)

Talk: Emergent phenomena in spin liquids.

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Sep. 2016 | Kanazawa

3 Talks: Spin-ice thin films, anisotropic kagome models and breathing lattices.

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Sep. 2016 | Taipei

Talk: Design of spin liquids in two and three dimensions.

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Jul. 2016 | Lyon

Sep. 2015 | Kansai

3 Talks: Multi-phase competition in Yb

_{2}Ti

_{2}O

_{7}, monopole crystal in Tb

_{2}Ti

_{2}O

_{7}and a kagome map of spin liquids.

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Jul. 2015 | Barcelona

Nov. 2014 | Kyoto

Jul. 2014 | Stockholm

Talk: Multi-phase competition in Yb

_{2}Ti

_{2}O

_{7}.

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Jul. 2014 | Cambridge

Apr. 2014 | Dresden

Mar. 2014 | Denver

Nov. 2013 | Saclay

*Matériaux et Interactions en Compétition*(GdR MICO)

Talk: A generic model for pyrochlores.

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Jul. 2013 | Seoul

Mar. 2013 | Hiroshima

Talk: Dimensional reduction in Yb

_{2}Ti

_{2}O

_{7}.

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Mar. 2013 | Baltimore

May. 2012 | Dresden

Talk: Loop models in the Coulomb phase coupled to itinerant electrons.

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Mar. 2012 | Boston

Oct. 2011 | Grenoble

Talk: Loop models in frustrated magnetism.

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Mar. 2011 | Dresden

Oct. 2010 | Budapest

Talk: Topological sector fluctuations

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Jun. 2010 | Orsay

May 2009 | Lyon

Mar. 2009 | Pittsburgh

Aug. 2007 | Trieste

The flag icons used on this page are coming from Free Flag Icons.

###### Open Ph.D. position

** Spin liquids and Topological phases **

We have an opening for a 3-year PhD fellowship in the field of condensed matter theory and statistical physics, starting in September 2019.

Figure: Evolution of the structure factor from a Coulomb gauge field (a,b) to a different spin liquid (c,d) when varying the coupling constant J of a kagome model. Taken from our work in PRL (2017).

We are looking for a serious and motivated student, with a Master in Physics, a solid background in condensed-matter and/or statistical physics, and an interest in simulations. The candidate is expected to be proficient in English and/or French. Informal inquiries are welcome. Please apply via the following website.

### Ludovic JAUBERT

Laboratoire Ondes et Matière d’Aquitaine (LOMA)

351 cours de la libération

33405 Talence Cedex

**Phone **: + 33 (0)5 40 00 3732

**E-mail**: ludovic.jaubert@u-bordeaux.fr