47 citations · 136 across the 8 of their papers we have counts for
8 papers
Spin orientation -- a subtle interplay between strain and multipole Coulomb interactions
Subhra Sen Gupta, Shinjini Paul, Suman Mandal +2
We address the technologically important issue of the spin orientation on a correlated magnetic surface and how to manipulate it. We consider a prototypical strongly correlated sys…
Beyond Nearest-neighbour Universality of Spectral Fluctuations in Quantum Chaotic and Complex Many-body Systems
Debojyoti Kundu, Santosh Kumar, Subhra Sen Gupta
Discerning chaos in quantum systems is an important problem as the usual route of Lyapunov exponents in classical systems is not straightforward in quantum systems. A standard rout…
Spectral Crossovers and Universality in Quantum Spin-chains Coupled to Random Fields
Debojyoti Kundu, Santosh Kumar, Subhra Sen Gupta
We study the spectral properties of and spectral-crossovers between different random matrix ensembles (Poissonian, GOE, GUE) in correlated spin-chain systems, in the presence of ra…
Signatures of spectral crossovers in the short- and long-range spectral correlations of a disordered spin-chain with Kramers degeneracy
Debojyoti Kundu, Santosh Kumar, Subhra Sen Gupta
We investigate several distinct spectral crossovers amongst various integrable and quantum-chaotic limits of a 1D disordered quantum spin-1/2 model, by tuning the relative amplitud…
Spin-Flop Ordering from Frustrated Ferro- and Antiferromagnetic Interactions: A Combined Theoretical and Experimental Study of a Monolayer
C. Grazioli, Dario Alfè, S. R. Krishnakumar +8
The occurrence of a noncollinear magnetic structure at a Mn monolayer grown epitaxially on Fe(100) is predicted theoretically, using spinor density-functional theory, and observed…
The importance of inter-site coherences in the x-ray absorption spectra of mixed-valent systems
Subhra Sen Gupta, Hiroki Wadati, G. A. Sawatzky
We study the importance of inter-site coherences and quantum interference effects in the x-ray absorption spectroscopy (XAS) of mixed-valent systems. We demonstrate its importance,…
Coexistence of Bound and Virtual-bound States in Shallow-core to Valence Spectroscopies
Subhra Sen Gupta, J. A. Bradley, M. W. Haverkort +3
We develop the theory for shallow-core to valence excitations when the multiplet spread is larger than the core-hole attraction, e.g., if the core and valence orbitals have the sam…
Probing Electronic Correlations in Actinide Materials Using Multipolar Transitions
J. A. Bradley, S. Sen Gupta, G. T. Seidler +7
We report nonresonant inelastic x-ray scattering from the semi-core 5d levels of several actinide compounds. Dipole-forbidden, high-multipole features form a rich bound-state spect…