Engineering the Kondo state in two-dimensional semiconducting phosphorene

Abstract

Correlated interaction between dilute localized impurity electrons with the itinerant host conduction electrons in metals gives rise to the conventional many-body Kondo effect below sufficiently low temperature. In sharp contrast to these conventional Kondo systems, we report an intrinsic, robust and high-temperature Kondo state in two-dimensional semiconducting phosphorene. While absorbed at a thermodynamically stable lattice defect, Cr impurity triggers an electronic phase transition in phosphorene to provide conduction electrons, which strongly interact with the localized moment generated at the Cr site. These manifests into intrinsic Kondo state, where the impurity moment is quenched at multi-stage and at temperatures in the 40-200 K range. Further, along with a much smaller extension of Kondo cloud, the predicted Kondo state is shown to be robust under uniaxial strain and layer thickness, which greatly simplifies its future experimental realization. We predict the present study will open up new avenues in Kondo physics and trigger further theoretical and experimental studies.

Exciton in phosphorene: Strain, impurity, thickness, and heterostructure

“…The effect of uniaxial strain on the electronic structure of SLP has been studied earlier within the conventional exchange-correlation functional. [20,63,65,66] However, the considerations of self-energy correction and electronhole interaction are scarce in this regard. Here, we investigate the QP and optical gaps; and the corresponding exciton binding for SLP under ε a/z s = ±5% uniaxial strain (Table I), while the strained lattice is relaxed along the transverse direction.…”

“…We earlier reported that the strain energy along the zigzag direction is much higher compared to the same along the armchair direction and thus, straining the SLP along the armchair direction is comparatively easier. [20] Within −5% ε a/z s +5% strain and optical E opt g gaps are calculated within the G2W0 and G2W0-BSE approaches, respectively, which are subsequently interpolated to Lz → ∞. The parameters for the simplified exciton model, the effective carrier masses m * e and m * h along the armchair and zigzag directions; and the average static dielectric constant are calculated within the HSE06 hybrid functional.…”

“…[12] Phosphorene has attracted a lot of attention due to its many plausible technological applications, [13][14][15][16][17] and has become an interesting proving ground for manybody physics. [18][19][20] The Dirac semimetal state has been experimentally realized in few-layer phosphorene under adatom absorption. [19] We have recently reported an intrinsic, robust and high-temperature Kondo state in defected phosphorene doped with a transition-metal impurity.…”

“…[19] We have recently reported an intrinsic, robust and high-temperature Kondo state in defected phosphorene doped with a transition-metal impurity. [20] In the present context, phosphorene has unique * These authors contributed equally † Corresponding author: mukul.kabir@iiserpune.ac.in optical properties that are mainly determined by the quasiparticle band structure and screening. Originating from a puckered honeycomb network, the electronic band structure is highly asymmetric in phosphorene and consequently, the optical properties are also found to be highly anisotropic.…”

Mechanistic insights in phosphorene degradation

“…[7,[12][13][14] Further, many exotic quantum manybody states have been theoretically predicted and experimentally demonstrated in few-layer phosphorene. [15][16][17] However, the major hurdle is the inferior stability of phosphorene at ambient conditions compared to graphene and transition-metal dichalcogenides. The degradation in two-dimension results from the dynamics of lattice defects and chemical interaction with the environment.…”