TCM
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Victor Jouffrey

 Victor Jouffrey

Victor Jouffrey

PhD student in Dr Castelnovo's group

Office: 545 Mott Bld
Phone: +44(0)1223 3 37275
Email: vatj2 @ cam.ac.uk

TCM Group, Cavendish Laboratory
19 JJ Thomson Avenue,
Cambridge, CB3 0HE UK.

Research

I study the physics of strongly correlated system and their out-of-equilibrium behaviour . I am particularly interested in a sub-category of frustrated magnets , the so-called quantum spin liquid. In these systems, the groundstate is massively degenerate and each groundstate is connected to a number of others by local transformations. The locality allows quantum fluctuations to generate tunnelling from one groundstate to another preventing conventional ordering in the system even at the lowest temperature. The low-temperature disordered phase, often referred to as quantum paramagnet or quantum spin liquid, display exotic phenomena such as fractionalized excitations, emergent gauge field, topological properties ...

At the moment, my work mainly focus on the effect of the coupling between a magnetic system and a thermal bath. In real solids, the role of the thermal bath is played by phonons which may interact with the magnetic degrees of freedom of the system via a magneto-elastic coupling. When the temperature of the bath is large compare to the energy scale of the magnetic system but their coupling is weak, interesting physical phenomena may arise.

In Plain English

Macroscopic objects are constituted of a large ensemble of ions and electrons interacting with one another. Condensed matter theory aims to understand how the collective behaviour of the microscopic constituents is related to the material properties, e.g. electric resistivity, elasticity... Magnets are actually constituted of a large number of smaller magnets, the spin of electrons, which aligns in the same direction to give rise to the macroscopic magnetic field. In frustrated magnets, the interplay between the crystal geometry and the interactions between the spins leads to exotic organisation, which in turn gives rise to new physics. Theorists study microscopic models using analytical or numerical tools to predict how the spins will organize and what will be the macroscopic properties of the material.