## Dr Sam T. CarrInstitut fur Theorie der Kondensierten MaterieUniversitat Karlsruhe Room: 10-08 Tel: ++49 721 608-7006 Email: carr@tkm.uni-karlsruhe.de |

- M. P. Schneider, S. T. Carr, I. V. Gornyi and A. D. Mirlin,
*Weak localization and magnetoresistance in a two-leg ladder model*, arXiv:1207.6337 (2012), (submitted to Phys. Rev. B) - J. M. Fellows, S. T. Carr, C. A. Hooley and J. Schmalian,
*Unbinding of giant vortices in states of competing order*, arXiv:1205.1333 (2012), (submitted to Phys. Rev. Lett.) - J. M. Fellows and S. T. Carr,
*Superfluid, solid, and supersolid phases of dipolar bosons in a quasi-one-dimensional optical lattice*, Phys. Rev. A**84**, 051602(R) (2011). - S. T. Carr, D. A. Bagrets and P. Schmitteckert,
*Full counting statistics in the self-dual interacting resonant level model*, Phys. Rev. Lett.**107**, 206801 (2011). - S. T. Carr, B. N. Narozhny and A. A. Nersesyan,
*The effect of a local perturbation in a fermionic ladder*, Phys. Rev. Lett.**106**, 126805 (2011). - S. T. Carr, J. Quintanilla and J. J. Betouras,
*Lifshitz transitions and crystallization of fully-polarised dipolar Fermions in an anisotropic 2D lattice*, Phys. Rev. B**82**, 045110 (2010). - S. T. Carr, J. Quintanilla and J. J. Betouras,
*Deconfinement and quantum liquid crystalline states of dipolar fermions in optical lattices*, Int. J. Mod. Phys. B**23**, 4074 (2009) (proceedings of conference CMT32 in Loughborough). - J. Quintanilla, S. T. Carr and J. J. Betouras,
*Meta-nematic, smectic and crystalline phases of dipolar fermions in an optical lattice*, Phys. Rev. A**79**, 031601(R) (2009). - S. T. Carr,
*Strong correlation effects in single wall carbon nanotubes*, Int. J. Mod. Phys. B**22**, 5235 (2008), (invited review article). - S. T. Carr, A. O. Gogolin and A. A. Nersesyan,
*Interaction induced dimerization in zigzag single wall carbon nanotubes*, Phys.Rev. B**76**245121 (2007). - S. T. Carr, B. N. Narozhny
and A. A. Nersesyan,
*Spinless fermionic ladders in a magnetic field: Phase diagram*, Phys. Rev. B**73**195114 (2006). - B. N. Narozhny, S. T. Carr
and A. A. Nersesyan,
*Fractional charge excitations in fermionic ladders*, Phys. Rev. B**71**161101 (2005). - S. T. Carr and A. M. Tsvelik,
*Spectrum and correlation functions of a quasi-one-dimensional quantum Ising model*, Phys. Rev. Lett.**90**, 177206 (2003). - S. T. Carr and A. M. Tsvelik,
*Superconductivity and Charge Density Wave in a Quasi-One-Dimensional Spin Gap System*, Phys. Rev. B**65**, 195121 (2002).

You can also find all these articles on the arXiv: Full list of articles on arXiv or at ResearcherID

**Non-perturbative solutions to quasi-one-dimensional strongly correlated
systems**

*Abstract* - In this thesis,
we deal with quasi-one-dimensional field theories by which we mean strongly
anisotropic higher dimensional models. One way to solve such quasi-one-dimensional
models is to split them into a one-dimensional part and a weaker inter-chain
perturbation on this. The one-dimensional model can then be solved exactly
by techniques such as bosonisation or integrability, and the weak inter-chain
part can be treated perturbatively by using the Random Phase Approximation
(RPA), or beyond this. This allows us to comment on concepts such as dimensional
crossover, and by treating the one-dimensional fluctuations exactly, we access
phases not accessible by conventional perturbation theory. In this thesis,
we report results for three such models: the first is a model of non-BCS
superconductivity where a spin-gap in the one dimensional chains leads to
pairing, even for repulsive interactions. We look at the interplay between
a superconducting and a charge density wave ground state. The second model
is that of a Mott insulator, where we are specifically looking at the effects
of a magnetic field on the model. We look at the density of states as the
angle of the magnetic field is varied. The third system is the quantum Ising
model, a generic model of two-state systems, where we calculate the correlation
functions in the ordered phase. All three models are motivated by reference
to real materials with a strong structural anisotropy.