We study a spin-1/2 system with Heisenberg plus ring exchanges on a four-leg triangular ladder using the density matrix renormalization group and Gutzwiller variational wave functions. Near an isotropic lattice regime, for moderate to large ring exchanges we find a spin Bose-metal phase with a spinon Fermi sea consisting of three partially filled bands. Going away from the triangular towards th...

Kirsi Majava and Xue-Cheng Tai [12] proposed a modified level set method for solving a free boundary problem associated with unilateral obstacle problems. The proximal bundle method and gradient method were applied to solve the nonsmooth minimization problems and the regularized problem, respectively. In this paper, we extend this approach to solve the bilateral obstacle problems and employ Run...

We study the spin ordering within the three-leg ladders present in the oxyborate Fe3O2BO3 consisting of localized classical spins interacting with conduction electrons (one electron per rung). We also consider the competition with antiferromagnetic superexchange interactions to determine the magnetic phase diagram. Besides a ferromagnetic phase we find (i) a phase with ferromagnetic rungs order...

In this manuscript, we proposed a novel framework of the q-rung orthopair fuzzy subfield (q-ROFSF) and illustrate that every Pythagorean is certain field. We extend theory discuss its diverse basic algebraic characteristics in detail. Furthermore, prove some fundamental results establish helpful examples related to them. Moreover, present homomorphic images pre-images under field homomorphism. ...

This paper investigates a novel fuzzy Petri nets (FPNs) method based on q-rung orthopair sets (q-ROFSs) to provide an efficient solution uncertain knowledge representation and reasoning. It not only improves FPN’s flexibility in parameter reasoning algorithms but also addresses the challenging problem that most FPNs cannot implement backward reasoning, which is common task reversely inferring c...

Supply chain management is to improve competitive stress. In today’s world, terms and customer sense have altered in favor of an environmentalist manner. As a result this, green supplier selection has become very important topic. the approach, agility, lean process, sustainability, environmental sensitivity, durability are pointed. Like classical problems, criteria generally emphasize selection...