Engineering bands of extended electronic states in a class of topologically disordered and quasiperiodic lattices

Pal, Biplab; Chakrabarti, Abhijit

doi:10.1016/j.physleta.2014.07.034

Cited by 13 publications

(10 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3(a). We have used a realspace renormalization group (RSRG) method [44,45] to compute the LDOS spectrum for the different spin channels. We can clearly observe that, the spin-up (↑) channel shows an absolutely continuous energy spectrum in between E = ∆ − 2t and E = ∆ + 2t (here we have taken ∆ = 0 and t = 1).…”

Section: Resultsmentioning

confidence: 99%

Quasiperiodic magnetic chain as a spin filter for arbitrary spin states

Pal

2019

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

We show that a quasiperiodic magnetic chain comprising magnetic atomic sites sequenced in Fibonacci pattern can act as a prospective candidate for spin filters for particles with arbitrary spin states. This can be achieved by tuning a suitable correlation between the amplitude of the substrate magnetic field and the on-site potential of the magnetic sites, which can be controlled by an external gate voltage. Such correlation leads to a spin filtering effect in the system, allowing one of the spin components to completely pass through the system while blocking the others over the allowed range of energies. The underlying mechanism behind this phenomena holds true for particles with any arbitrary spin states S = 1, 3/2, 2, . . ., in addition to the canonical case of spinhalf particles. Our results open up the interesting possibility of designing a spin demultiplexer using a simple quasiperiodic magnetic chain system. Experimental realization of this theoretical study might be possible by using ultracold quantum gases, and can be useful in engineering new spintronic devices.

show abstract

Section: Resultsmentioning

confidence: 99%

Quasiperiodic magnetic chain as a spin filter for arbitrary spin states

Pal

2019

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…It turns out that the spin polarized transport in such aperiodic, quasi 1-d, quantum networks is intimately connected to a complete delocalization of the single particle states under certain resonance conditions, subtle and unusual. This is a non trivial variation of the canonical case of Anderson localization, 23 which has recently been pointed out in the literature, [24][25][26] and plays a crucial role in this analysis.…”

Section: Introductionmentioning

confidence: 89%

Flux-driven and geometry-controlled spin filtering for arbitrary spins in aperiodic quantum networks

2018

Self Cite

View full text Add to dashboard Cite

We demonstrate that an aperiodic array of certain quantum networks comprising magnetic and non-magnetic atoms can act as perfect spin filters for particles with arbitrary spin state. This can be achieved by introducing minimal quasi-one dimensionality in the basic structural units building up the array, along with an appropriate tuning of the potential of the non-magnetic atoms, the tunnel hopping integral between the non-magnetic atoms and the backbone, and, in some cases, by tuning an external magnetic field. This latter result opens up the interesting possibility of designing a flux controlled spin de-multiplexer using quantum networks. The proposed networks have close resemblance with a family of recently developed photonic lattices, and the scheme for spin filtering can thus be linked, in principle, to a possibility of suppressing any one of the two states of polarization of a single photon, almost at will. We use transfer matrices and a real space renormalization group scheme to unravel the conditions under which any aperiodic arrangement of such topologically different structures will filter out any given spin projection. Our results are analytically exact, and corroborated by extensive numerical calculations of the spin polarized transmission and the density of states of such systems.

show abstract

“…This interference enables high-performance molecular switching with large on/off ratios essential for the next generation of molecular electronics [110,111], where the RSRM has been used for the study of Fibonacci arrays of Aharonov-Bohm rings [112], metal-insulator transition in the quasiperiodic Aubry model [113], electronic transmission in bent quantum wires [114], and in ladders with a single side-attached impurity [115]. Recently, the electronic density of states, localization, transmittance, and persistent current in molecular chains and ladders have been widely investigated via RSRM [116][117][118][119][120][121][122], while the spin-selective electronic transport was also analyzed [123,124]. A review of these studies is presented in [125].…”

Section: Multidimensional Aperiodic Latticesmentioning

confidence: 99%

Real Space Theory for Electron and Phonon Transport in Aperiodic Lattices via Renormalization

Sánchez

Wang

2020

Symmetry

View full text Add to dashboard Cite

Structural defects are inherent in solids at a finite temperature, because they diminish free energies by growing entropy. The arrangement of these defects may display long-range orders, as occurring in quasicrystals, whose hidden structural symmetry could greatly modify the transport of excitations. Moreover, the presence of such defects breaks the translational symmetry and collapses the reciprocal lattice, which has been a standard technique in solid-state physics. An alternative to address such a structural disorder is the real space theory. Nonetheless, solving 1023 coupled Schrödinger equations requires unavailable yottabytes (YB) of memory just for recording the atomic positions. In contrast, the real-space renormalization method (RSRM) uses an iterative procedure with a small number of effective sites in each step, and exponentially lessens the degrees of freedom, but keeps their participation in the final results. In this article, we review aperiodic atomic arrangements with hierarchical symmetry investigated by means of RSRM, as well as their consequences in measurable physical properties, such as electrical and thermal conductivities.

show abstract

Engineering bands of extended electronic states in a class of topologically disordered and quasiperiodic lattices

Cited by 13 publications

References 54 publications

Quasiperiodic magnetic chain as a spin filter for arbitrary spin states

Quasiperiodic magnetic chain as a spin filter for arbitrary spin states

Flux-driven and geometry-controlled spin filtering for arbitrary spins in aperiodic quantum networks

Real Space Theory for Electron and Phonon Transport in Aperiodic Lattices via Renormalization

Contact Info

Product

Resources

About