Degeneracies and exotic phases in an isotropic frustrated spin-1/2 chain

Multipolar phase in frustrated spin-1/2 and spin-1 chains

“…The phase boundary of the quadrupolar and the VC phase is estimated using the level crossing or magnetic step criterion as in ref. [3,27]. For α ≥ 0.4 results will be discussed in the later part of this section.…”

“…We have shown the gs degeneracies in the odd S z sectors [27], but dimer order parameter B is vanishingly small in this sector. The existence of quadrupolar phase in spin-1 systems is controversial, as steps of two in magnetization-h curve is absent [44,45], whereas the other studies for general spin show the existence of this phase.…”

“…(1) consists of numerous phases such as the vector chiral (VC) [1,27], the dimer [5][6][7][8][9][10][12][13][14][15][16][17][18][19][20][21], the decoupled chain [8,18], and multipolar/SDW n phases [3,4]. In this paper, the SN/SDW 2 phase and other higher order multipolar phases are discussed.…”

“…In the large J 2 /J 1 regime, field theoretical calculations show that the SDW 2 phase exist in low magnetic field, whereas SN phase exists in the narrow range of magnetic field near the saturation field [3]. The numerical calculations in J 2 /|J 1 | = α > 0.6 show the finite binding energy of magnon even for a small field [27].…”

“…The model with a ferromagnetic J 1 shows many interesting phases like spin liquid [5][6][7][8][9], dimer [5][6][7][8][9], chiral vector [1,27], spin multipolar [3,4], decoupled phase [8]. The spin liquid phase is gapless and possesses quasilong range order [9,14].…”