Search arXivSearch

arXiv · 2609.08146

Transport properties and topological phase transitions for a Creutz-Su-Schrieffer-Heeger ladder

Abstract

In this work, we investigate the electronic, topological, and transport properties of a Creutz-Su-Schrieffer-Heeger (CSSH) ladder. Using a tight-binding model within the Green's function formalism, we calculate the energy spectrum, local density of states (LDOS), and electronic transmission. We first determine the energy spectrum of the CSSH ladder and analyze the different topological phases present in the system, identifying one trivial phase and three distinct nontrivial regions. We then study electronic transport and show that the transmission reproduces the different topological phases through characteristic transport signatures. Finally, we derive the conditions for the emergence of non-topological flat bands and demonstrate that these bands also provide the necessary conditions for the formation of bound states in the continuum (BICs). Our results establish a direct connection between the topological properties, flat-band formation, and electronic transport in the CSSH ladder.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K. A. González, S. Bravo, L. Rosales, P. A. Orellana. 2026-09-08. Transport properties and topological phase transitions for a Creutz-Su-Schrieffer-Heeger ladder. https://arxiv.org/abs/2609.08146

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Spin-Axis Dynamic Locking

The all-electrical realization of highly spin-polarized currents and their efficient conversion into pure spin currents remains a fundamental challenge in spintronics. Here, we report a spin-axis dynamic locking (SADL) effect in altermagnets that pins the high and dynamically robust spin polarization to the crystalline axes: an in-plane electric field along one principal axis drives a highly spin-up-polarized current, whereas along the orthogonal axis, it generates a symmetry-enforced, equal-magnitude spin-down current. Consequently, applying an electric field diagonally yields a transverse pure spin current, reaching 100% charge-to-spin conversion in the ideal limit. Mechanistically, SADL originates from a spin-split tent-state band structure whose Lifshitz transitions delimit an open-Fermi-line regime. The momentum-separated Fermi lines carry orthogonal nonzero winding vectors, producing a pronounced velocity contrast while suppressing ordinary backscattering to dynamically stabilize the axial spin selectivity. High-throughput first-principles screening confirms SADL in broad materials. Notably, monolayer Cr2WSe4 and synthesized bulk (BaF)2Mn2Se2O exhibit efficiencies close to the ideal limit, paving the way for ultra-low-power, reconfigurable spintronic devices where the spin states are governed solely by electric field orientation.

cond-mat.other

Antisymmetric spontaneous resistivity anisotropy due to hard-axis collapse in polycrystalline Co thin films

We investigate magnetoresistance phenomena associated with the magnetization hard-axis collapse in polycrystalline Co thin films. Transport measurements reveal that, for specific orientations of the applied magnetic field, the system exhibits distinct remanent resistance levels in both the in-plane longitudinal and transverse voltage responses. In particular, the planar Hall resistance shows multiple stable and reproducible levels at room temperature, enabling the identification of at least three remanent states that can be distinguished and used for information storage. These resistance levels originate from non-uniform magnetic configurations stabilized after the application and removal of the external magnetic field in the hard-axis region. Since this phenomenon remains largely unexplored, we present an incipient study addressing its potential implications from an applied-physics perspective. The observation of such behavior in polycrystalline Co thin films grown on Si substrates suggests a simple and low-cost platform for spintronic memory and sensing devices based on the remanent planar Hall effect.

cond-mat.other

Exact Phase-Space Rotation in the Trapped Quantum Calogero Model

We develop a microscopic phase-space description of the quantum Calogero model in the presence of an external harmonic confining potential. Building on the quantum Lax-pair structure, we construct a Hermitian Wigner operator whose expectation value obeys the exact phase-space evolution equation d_t rho + lambda d_x rho - Omega^2 x d_lambda rho = 0 for arbitrary initial states and to all orders in the interaction strength. The resulting dynamics is a rigid rotation in phase space with period 2 pi/Omega, providing a microscopic realization of the isochronous dynamics of the trapped Calogero model. We further show that the moments of the phase-space density form rotating multiplets rather than independent conserved quantities. In particular, within the quadratic sector, the unique conserved combination is proportional to the trapped Hamiltonian, providing a nontrivial consistency check of the construction. In the limit Omega -> 0, the equation reduces to the exact free-streaming equation of the untrapped model.

cond-mat.other