Diversification in Indian agriculture towards high-value crops: The role of smallholders

"Agricultural diversification towards high-value crops can potentially increase farm incomes, especially in a country like India where demand for high-value food products has been increasing more quickly than that for staple crops. Indian agriculture is overwhelmingly dominated by smallholders, and researchers have long debated the ability of a smallholder-dominated subsistence farm economy to diversify into riskier high-value crops. Here, we present evidence that the gradual diversification of Indian agriculture towards high-value crops exhibits a pro-smallholder bias, with smallholders playing a proportionally larger role in the cultivation of vegetables versus fruits. The observed patterns are consistent with simple comparative advantage-based production choices. The comparatively high labor endowments of the small farmers, as reflected in their greater family sizes, induce them to diversify towards vegetables. Although fruit cultivation is also labor intensive (as compared to cultivation of staples), fruits are relatively capital intensive, making them a less advantageous choice for smallholders who tend to have low capital endowments. Furthermore, both the probability of participation in fruit and vegetable cultivation as well as land allocation to horticulture decreases with the size of landholdings in India. Small or medium holders do not appear to allocate a greater share of land to fruits or vegetables. However, the share allocated to vegetables is significantly higher if the family size is bigger, while the reverse is true in the case of fruits." from Authors' Abstractdiversification, Smallholders, small farms, High value agriculture,

Robust pseudogap across the magnetic field driven superconductor to insulator-like transition in strongly disordered NbN films

We investigate the magnetic field evolution of the superconducting state in a strongly disordered NbN thin film which exhibits a magnetic field tuned superconductor to insulator-like transition, employing low temperature scanning tunneling spectroscopy (STS). Transport measurements of the sample reveals a characteristic magnetic field, which separates the low field state where resistance decreases with decreasing temperature, i.e. dR/dT > 0 and a high-field state where dR/dT < 0. However, STS imaging of the superconducting state reveals a smooth evolution across this field and the presence of a robust pseudogap on both sides of this characteristic field. Our results suggest that the superconductor-insulator transition might be a percolative transition driven by the shrinking of superconducting fraction with magnetic field.Comment: 22 pages, 8 figures including supplementary materia

Quantum phase transition in few-layer NbSe2_2 probed through quantized conductance fluctuations

We present the first observation of dynamically modulated quantum phase transition (QPT) between two distinct charge density wave (CDW) phases in 2-dimensional 2H-NbSe$_2$. There is recent spectroscopic evidence for the presence of these two quantum phases, but its evidence in bulk measurements remained elusive. We studied suspended, ultra-thin \nbse devices fabricated on piezoelectric substrates - with tunable flakes thickness, disorder level and strain. We find a surprising evolution of the conductance fluctuation spectra across the CDW temperature: the conductance fluctuates between two precise values, separated by a quantum of conductance. These quantized fluctuations disappear for disordered and on-substrate devices. With the help of mean-field calculations, these observations can be explained as to arise from dynamical phase transition between the two CDW states. To affirm this idea, we vary the lateral strain across the device via piezoelectric medium and map out the phase diagram near the quantum critical point (QCP). The results resolve a long-standing mystery of the anomalously large spectroscopic gap in NbSe$_2$

Influence of anti-site disorder and electron-electron correlations on the electronic structure of CeMnNi4_4

CeMnNi$_4$ exhibits an unusually large spin polarization, but its origin has baffled researchers for more than a decade. We use bulk sensitive hard x-ray photoelectron spectroscopy (HAXPES) and density functional theory based on the Green's function technique to demonstrate the importance of electron-electron correlations of both the Ni 3$d$ ($U_{Ni}$) and Mn 3$d$ ($U_{Mn}$) electrons in explaining the valence band of this multiply correlated material. We show that Mn-Ni anti-site disorder as well as $U_{Ni}$ play crucial role in enhancing its spin polarization: anti-site disorder broadens a Ni 3$d$ minority-spin peak close to the Fermi level ($E_F$), while an increase in $U_{Ni}$ shifts it towards $E_F$, both leading to a significant increase of minority-spin states at $E_F$. Furthermore, rare occurrence of a valence state transition between the bulk and the surface is demonstrated highlighting the importance of HAXPES in resolving the electronic structure of materials unhindered by surface effects.Comment: Manuscript and Supplementary material, 13 pages, 17 figure