Controlling Luttinger liquid physics in spin ladders under a magnetic field.
We present a 14N nuclear magnetic resonance study of a single crystal of CuBr4(C5H12N)2 (BPCB) consisting of weakly coupled spin-1/2 Heisenberg antiferromagnetic ladders. Treating ladders in the gapless phase as Luttinger liquids, we are able to fully account for (i) the magnetic field dependence of the nuclear spin-lattice relaxation rate T1(-1) at 250 mK and for (ii) the phase transition to a 3D ordered phase occurring below 110 mK due to weak interladder exchange coupling. BPCB is thus an excellent model system where the possibility to control Luttinger liquid parameters in a continuous manner is demonstrated and the Luttinger liquid model tested in detail over the whole fermion band.
Grenoble High Magnetic Field Laboratory, CNRS, F-38042 Grenoble Cedex 09, France.
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M
Klanjsek
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H
Mayaffre
C
C
Berthier
M
M
Horvatić
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B
Chiari
O
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Piovesana
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P
Bouillot
C
C
Kollath
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E
Orignac
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Citro
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Giamarchi