@article{ISI:000182019300098,
 abstract = {We study the anisotropic Heisenberg (XYZ) spin-1/2 chain placed in a
magnetic field pointing along the x axis. We use bosonization and a
renormalization group analysis to show that the model has a nontrivial
fixed point at a certain value of the XY anisotropy a and the magnetic
field h. Hence there is a line of critical points in the (a,h) plane on
which the system is gapless, even though the Hamiltonian has no
continuous symmetry. The quantum critical line corresponds to a
spin-flip transition; it separates two gapped phases in one of which the
Z(2) symmetry of the Hamiltonian is broken. Our study has a bearing on
one of the transitions of the axial next-nearest neighbor Ising chain in
a transverse magnetic field. We also discuss the properties of the model
when the magnetic field is increased further, in particular, the
disorder line on which the ground state is a direct product of single
spin states.},
 article-number = {094435},
 author = {Dutta, A and Sen, D},
 doi = {10.1103/PhysRevB.67.094435},
 eissn = {2469-9969},
 issn = {2469-9950},
 journal = {PHYSICAL REVIEW B},
 month = {MAR 1},
 number = {9},
 times-cited = {21},
 title = {Gapless line for the anisotropic Heisenberg spin-(1)/(2) chain in a
magnetic field and the quantum axial next-nearest-neighbor Ising chain},
 unique-id = {ISI:000182019300098},
 volume = {67},
 year = {2003}
}