I am a postdoctoral researcher working with Jasper van Wezel in the University of Amsterdam. Previously, I was working with Prof. Dr. Arno P. Kampf and Prof. Dr. Thilo Kopp at the University of Augsburg, and Dr. Catherine Pépin at the Institut de Physique Théorique, CEA, Université Paris-Saclay. My PhD was supervised by Prof. Siddharth S. Saxena (Quantum Matter Group) and Prof. Emilio Artacho (Theory of Condensed Matter Group) and funded by the EPSRC and Corpus Christi College at the Cavendish Laboratory, University of Cambridge.

Below is a description of my current and past research interests:

I am currently investigating the influence of finite thickness on properties of topological insulators.

We studied this using a minimal model for topological insulators in a slab geometry. One parameter of our model, namely the Dirac velocity perpendicular to the slab, distinguishes between two qualitatively distinct situations: when it is zero, we find that the topological invariants of the 3D system can be entirely deduced from properties of the slab. However when it is not zero, a new phase arises, with surface states but without band inversion. We also investigated this model for large dispersions perpendicularly to the slab and unveiled a regime where the slab displays non-trivial topological invariants but nonetheless extrapolates towards a trivial 3D state.

__C. Morice__, T. Kopp, A. P. Kampf

Non-unique connection between bulk topological invariants and surface physics

Phys. Rev. B 100, 235427 (2019)

At very low temperature, novel quantum effects arise and display mesmerising physics. In particular, close to quantum phase transitions, quantum fluctuations modify properties even at high temperature. The proximity to two quantum phase transitions instead of one could therefore lead to very interesting phenomena. I studied systems where two order parameters are coupled, close to both their quantum phase transitions.

We found that, if the coupling between order parameters is biquadratic, the susceptibilities of both order parameter fields have the same critical exponent over a wide temperature range, even if the exponents of the non-coupled order parameters are different. This finding strongly challenges the conventional characterization of a quantum phase transition in terms of asymptotic exponents.

__C. Morice__, P. Chandra, S. E. Rowley, G. Lonzarich and S. S. Saxena

Hidden fluctuations close to a quantum bicritical point

Phys. Rev. B 96, 245104 (2017)

Cuprates have attracted great attention since they were shown to display superconductivity at a remarkably high temperature, above 150 K in some cases. However the process causing this phenomenon is not properly understood yet.

A theory based on an SU(2) order parameter for the pseudogap has been able to explain a series of features of the phase diagram of these materials. We showed that it matches many recently discovered features of both transport and photoemission measurements. Moreover, the study of the topology of the SU(2) field allowed us to properly describe charge modulations, the multiplicity of transitions at the pseudogap temperature, the B-T phase diagram, as well as to predict how to probe experimentally a signature of this theory.

__C. Morice__, D. Chakraborty, and C. Pépin

Collective mode in the SU(2) theory of cuprates

Phys. Rev. B 98, 224514 (2018)

__C. Morice__, D. Chakraborty, X. Montiel, and C. Pépin

Pseudo-spin Skyrmions in the Phase Diagram of Cuprate Superconductors

J. Phys.: Condens. Matter 30 (2018) 295601

D. Chakraborty, __C. Morice__, and C. Pépin

The phase diagram of the underdoped cuprates at high magnetic field

Phys. Rev. B 97, 214501 (2018)

__C. Morice__, X. Montiel, and C. Pépin

Evolution of spectral and transport quantities with doping in the SU(2) theory of cuprates

Phys. Rev. B 96, 134511 (2017)

Materials based on bismuth-sulphur layers were found to be superconducting at up to 10 K, as well as exhibiting quantum fluctuations. I probed superconductivity and other phenomena such as magnetism and charge density wave in these materials, using ab-initio techniques such as Density Functional Theory (DFT) and Density Functional Theory for Superconductors (SCDFT).

Highlights of this work include strong evidence for the presence of an unconventional pairing mechanism, the calculation of a magnetic instability in some lanthanide compounds, a prediction of pressure-induced superconductivity and the explanation of the doping mechanism in a stoichiometric material.

__C. Morice__, R. Akashi, T. Koretsune, S. S. Saxena and R. Arita

Weak phonon-mediated pairing in BiS_{2} superconductor from first principles

Phys. Rev. B Rapid Comm. 95, 180505(R) (2017)

__C. Morice__, E. Artacho, S. E. Dutton, H.-J. Kim and S. S. Saxena

Electronic and magnetic properties of superconducting LnO_{1-x}F_{x}BiS_{2} (Ln = La, Ce, Pr, and Nd) from first principles

J. Phys.: Condens. Matter 28 (2016) 345504

__C. Morice__, E. Artacho and S. S. Saxena

Electronic structure predictions in Bi-O-S systems

Nov. Supercond. Mater. 1, 75-78 (2015)

T. Sugimoto, D. Ootsuki, __C. Morice__, E. Artacho, S. S. Saxena, E. F. Schwier, M. Zheng, Y. Kojima, H. Iwasawa, K. Shimada, M. Arita, H. Namatame, M. Taniguchi, M. Takahashi, N. L. Saini, T. Asano, R. Higashinaka, T. D. Matsuda, Y. Aoki, and T. Mizokawa

Fermi surfaces and orbital polarization in superconducting CeO_{0.5}F_{0.5}BiS_{2} revealed by angle-resolved photoemission spectroscopy

Phys. Rev. B 92, 041113(R) (2015)

__C. Morice__, E. Artacho, S. E. Dutton, D. Molnar, H.-J. Kim and S. S. Saxena

Effects of stoichiometric doping in superconducting Bi-O-S compounds

J. Phys.: Condens. Matter 27 (2015) 135501

University of Amsterdam, November 2019, Amsterdam, The Netherlands

ESPCI, October 2019, Paris, France

Université Paris-Sud, April 2019, Orsay, France

Emergent Phenomena in Strongly Correlated Quantum Matter 2018, Natal, Brazil

International Conference on Superconductivity and Magnetism 2018, Antalya, Turkey

University of Bristol, November 2017, Bristol, United Kingdom

Université de Sherbrooke, September 2017, Sherbrooke, Québec, Canada

Université Paris-Sud, June 2017, Orsay, France

University of Cambridge, March 2017, Cambridge, United Kingdom

University of Amsterdam, May 2016, Amsterdam, The Netherlands

Max Planck Institute of Microstructure Physics, April 2016, Halle, Germany

Jagiellonian University, September 2015, Krakow, Poland

Signatures of Topology in Condensed Matter 2019, Trieste, Italy

Strongly Correlated Electron Systems 2017, Prague, Czech Republic

Matériaux, Etats Electroniques, Interactions et Couplages non-Conventionnels 2017, Bordeaux, France

Deutsche Physikalische Gesellschaft Spring Meeting 2015, Berlin, Germany

American Physical Society March Meeting 2015, San Antonio, Texas, USA

Donostia International Conference on Nanoscale Magnetism and Applications 2013, San Sebastian, Spain

Cutting-Edge Topics in Quantum Materials 2017, Paris, France

Strongly Correlated Electron Systems 2017, Prague, Czech Republic

10th anniversary of the ERC at Paris-Saclay University, Saclay, France

Gordon Research Conference on Correlated Electron Systems 2016, Mount Holyoke, USA

International Conference on Magnetism 2015, Barcelona, Spain

Strongly Correlated Electron Systems 2014, Grenoble, France

Bernard Coqblin Memorial Symposium 2013, Paris, France

Strongly Correlated Electron Systems 2013, Tokyo, Japan