We study the S=1/2 Heisenberg model on the triangular lattice with nearest
neighbor interaction J1 and next nearest neighbor interaction J2 with the
density matrix renormalization group. We are able to study long open cylinders
with widths up to 9 lattice spacings. At an intermediate J2 region 0.06≲J2/J1≲0.17, we find evidence for a spin liquid (SL) state
with short range spin-spin, bond-bond and chiral correlation lengths, bordered
by a classical 120∘ N\'eel ordered state at small J2 and by a two
sub-lattice collinear magnetically ordered state at larger J2. Focusing on
J2/J1=0.1, we find a number of signatures of a gapped SL phase: two
quasi-degenerate ground states on even cylinders, with an energy gap that
decreases exponentially with the cylinder width; a dimerization effect on odd
cylinders; and large spin triplet and singlet bulk gaps.Comment: 5+4 pages, 4+7 figures, 1 table. v2 minor changes made for
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