Krishnakumar S. R. Menon
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Krishnakumar S. R. Menon has a total of 70 co-authors. Here are the top co-authors by number of shared publications:
- Suman Mandal
Department of Physics, Sabang Sajanikanta Mahavidyalaya, Lutunia, West Bengal 721166, India
16 shared publications - Sanjoy Kr Mahatha
UGC-DAE Consortium for Scientific Research , Khandwa Road
10 shared publications Jayanta Das
Department of Physics, Maharaja College, Ara, Bihar, 802301, India
9 shared publicationsAsish K. Kundu
8 shared publicationsSukanta Barman
Department of Physics, Raja Peary Mohan College, Hooghly, INDIA
8 shared publicationsSuvankar Chakraborty
8 shared publications
Latest Publications
- 4 September 2025
- Published by American Physical Society (APS) in Physical Review B
- Vol. 112 (11)
Strain-mediated growth dynamics and electronic structure evolution of Ag films on by low-energy electron microscopy- 4 September 2025
- Published by American Physical Society (APS) in Physical Review B
- Vol. 112 (11)
Strain-mediated growth dynamics and electronic structure evolution of Ag films on by low-energy electron microscopy- 30 July 2025
- Published by American Physical Society (APS) in Physical Review B
- Vol. 112 (4)
Evolution of the atomic and electronic structure of the bimetallic surface alloy: A LEED, ARPES, and DFT study- 30 July 2025
- Published by American Physical Society (APS) in Physical Review B
- Vol. 112 (4)
Evolution of the atomic and electronic structure of the bimetallic surface alloy: A LEED, ARPES, and DFT study- Open Access
- 25 April 2025
- Published by Springer Nature in Indian Journal of Physics
- Vol. 99 (10) , 3755-3760
Growth and characterization of Ag layers on Mo(110) using LEED, XPS and ARPES
Epitaxial ultra-thin film systems present unique properties distinct from their bulk counterparts, influenced by strain, morphology, defects, and substrate conditions. The Ag/Mo(110) system, where silver adopts a face-centred cubic (fcc) structure on a body-centred cubic (bcc) substrate, is an interesting system for studying as it forms twin Ag(111) planes with their lattice parameters varying depending on the thickness of the silver layer. This study investigates the properties of a 30 monolayer silver film epitaxially grown on Mo(110) surface at room temperature utilizing low energy electron diffraction, x-ray photoelectron spectroscopy, and angle-resolved photoemission spectroscopy (ARPES). The presence of Shockley surface state in the ARPES data indicates that the grown Ag(111) planes are of high quality in our deposition condition. We also compare the electronic structure with single crystal Ag(111) substrate, highlighting its potential for tunable substrate applications.
- 25 April 2025
- Published by Springer Nature in Indian Journal of Physics
- Vol. 99 (10) , 3755-3760
Open AccessGrowth and characterization of Ag layers on Mo(110) using LEED, XPS and ARPES
Epitaxial ultra-thin film systems present unique properties distinct from their bulk counterparts, influenced by strain, morphology, defects, and substrate conditions. The Ag/Mo(110) system, where silver adopts a face-centred cubic (fcc) structure on a body-centred cubic (bcc) substrate, is an interesting system for studying as it forms twin Ag(111) planes with their lattice parameters varying depending on the thickness of the silver layer. This study investigates the properties of a 30 monolayer silver film epitaxially grown on Mo(110) surface at room temperature utilizing low energy electron diffraction, x-ray photoelectron spectroscopy, and angle-resolved photoemission spectroscopy (ARPES). The presence of Shockley surface state in the ARPES data indicates that the grown Ag(111) planes are of high quality in our deposition condition. We also compare the electronic structure with single crystal Ag(111) substrate, highlighting its potential for tunable substrate applications.
- 10 December 2024
- Published by Elsevier in Applied Surface Science
- Vol. 685
Residue-free layered material interfaces for device processing
- 10 December 2024
- Published by Elsevier in Applied Surface Science
- Vol. 685
Residue-free layered material interfaces for device processing
- 19 November 2024
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 26 (47) , 29595-29603
Tuning the electronic dimensionality and bandgap in Cs2AgBiX6 (X = Br, Cl) for photovoltaic applications: a DFT-1/2 study of cation disorder
Impact of cation disorder in tuning the electronic dimensionality of Cs2AgBiX6 studied using DFT-1/2 and COHP analysis. A fractional (non-integer) electronic dimensionality concept emerges as a key factor in governing the optoelectronic properties.
- 19 November 2024
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 26 (47) , 29595-29603
Tuning the electronic dimensionality and bandgap in Cs2AgBiX6 (X = Br, Cl) for photovoltaic applications: a DFT-1/2 study of cation disorder
Impact of cation disorder in tuning the electronic dimensionality of Cs2AgBiX6 studied using DFT-1/2 and COHP analysis. A fractional (non-integer) electronic dimensionality concept emerges as a key factor in governing the optoelectronic properties.
- 21 October 2024
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 26 (43) , 27735-27740
Hole-states in Li doped NiO: doping dependence of Zhang-Rice spectral weight
We report on structural evolution and a dynamical transfer of spectral weight as observed in O K-edge X-ray absorption (XA) spectra upon hole doping in LixNi1−xO (0 ≤ x ≤ 0.24). We find that the unit cell of doped NiO evolves in a specific way up to an intermediate doping level (x = 0.12) and then follows a different trend. A double peak structure (one is localized and the other is more delocalized) of low energy spectral weight (LESW) at the O K-edge is identified and quantified. Normalized LESW is found to increase linearly with an effective doping concentration (∼x/(1 − 2x)) with a change in slope at x = 0.12, which is correlated to the observed structural evolution. Doping dependence of Ni L3-edge XA spectral shape closely follows the localized peak of LESW at the O K-edge. Our observations strongly support the Zhang-Rice (ZR) picture, confirming that doped holes in NiO are of primarily ZR character. Furthermore, we find that Fe co-doping destroys the ZR spectral weight and recovers the spectral shapes to that of NiO.
- 21 October 2024
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 26 (43) , 27735-27740
Hole-states in Li doped NiO: doping dependence of Zhang-Rice spectral weight
We report on structural evolution and a dynamical transfer of spectral weight as observed in O K-edge X-ray absorption (XA) spectra upon hole doping in LixNi1−xO (0 ≤ x ≤ 0.24). We find that the unit cell of doped NiO evolves in a specific way up to an intermediate doping level (x = 0.12) and then follows a different trend. A double peak structure (one is localized and the other is more delocalized) of low energy spectral weight (LESW) at the O K-edge is identified and quantified. Normalized LESW is found to increase linearly with an effective doping concentration (∼x/(1 − 2x)) with a change in slope at x = 0.12, which is correlated to the observed structural evolution. Doping dependence of Ni L3-edge XA spectral shape closely follows the localized peak of LESW at the O K-edge. Our observations strongly support the Zhang-Rice (ZR) picture, confirming that doped holes in NiO are of primarily ZR character. Furthermore, we find that Fe co-doping destroys the ZR spectral weight and recovers the spectral shapes to that of NiO.
- 3 May 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 109 (19) , 195111
Spin-selective evolution of the Zhang-Rice state in binary transition metal oxide MnO(001) film
The Zhang-Rice (ZR) state is a strongly hybridized bound state formed by transition-metal and oxygen atoms. The spin fluctuations within the ZR state are known to play an important role in high- superconductivity in cuprates. Here, we employ a combination of angle-resolved photoemission spectroscopy (ARPES), x-ray photoemission spectroscopy (XPS), and ab initio embedded dynamical mean-field theory (eDMFT) to investigate the influence of magnetic ordering on the spectral characteristics of the valence band and Mn core-level in MnO (001) ultrathin films. Our results demonstrate that a complex spin-selective evolution of Mn hybridization develops due to the long-range antiferromagnetic (AFM) ordering. This hybridization significantly alters the spectral shape and weight of the ZR state. Specifically, in the AFM phase, we observed the sharpening of the ZR state and band folding with the periodicity of the AFM unit cell of MnO(001). We also demonstrated a strong connection between the spectral evolution of the ZR state and the non-local screening channels of the photoexcited core holes. Further, our detailed temperature-dependent study reveals the presence of short-range antiferromagnetic correlations that exist at much higher temperatures than Neel temperature and shows the evolution of the ZR state across the magnetic transitions and its implication to the core-hole screening in binary transition metal oxides.- 3 May 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 109 (19) , 195111
Spin-selective evolution of the Zhang-Rice state in binary transition metal oxide MnO(001) film
The Zhang-Rice (ZR) state is a strongly hybridized bound state formed by transition-metal and oxygen atoms. The spin fluctuations within the ZR state are known to play an important role in high- superconductivity in cuprates. Here, we employ a combination of angle-resolved photoemission spectroscopy (ARPES), x-ray photoemission spectroscopy (XPS), and ab initio embedded dynamical mean-field theory (eDMFT) to investigate the influence of magnetic ordering on the spectral characteristics of the valence band and Mn core-level in MnO (001) ultrathin films. Our results demonstrate that a complex spin-selective evolution of Mn hybridization develops due to the long-range antiferromagnetic (AFM) ordering. This hybridization significantly alters the spectral shape and weight of the ZR state. Specifically, in the AFM phase, we observed the sharpening of the ZR state and band folding with the periodicity of the AFM unit cell of MnO(001). We also demonstrated a strong connection between the spectral evolution of the ZR state and the non-local screening channels of the photoexcited core holes. Further, our detailed temperature-dependent study reveals the presence of short-range antiferromagnetic correlations that exist at much higher temperatures than Neel temperature and shows the evolution of the ZR state across the magnetic transitions and its implication to the core-hole screening in binary transition metal oxides.- 21 March 2024
- Published by Elsevier in Thin Solid Films
- Vol. 795
Tin oxide thin films on Ag(111): Thickness and temperature dependent study of surface structure and electronic properties
- 21 March 2024
- Published by Elsevier in Thin Solid Films
- Vol. 795
Tin oxide thin films on Ag(111): Thickness and temperature dependent study of surface structure and electronic properties
- 16 January 2023
- Published by Springer Nature in Indian Journal of Physics
- Vol. 97 (8) , 2395-2404
Material surface characterization using low-energy electron microscopy and photoemission electron microscopy
- 16 January 2023
- Published by Springer Nature in Indian Journal of Physics
- Vol. 97 (8) , 2395-2404
Material surface characterization using low-energy electron microscopy and photoemission electron microscopy
- 22 December 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 106 (23) , 235146
Polarization-dependent electronic structure of Ag quantum well states on the (0001) surface using ARPES and DFT studiesThe electronic band structure of clean and Ag-induced quantum well states on the (0001) surface has been investigated using polarization-dependent angle-resolved photoemission spectroscopy (ARPES) along with first-principle-based density functional theory (DFT) calculations. Using selective linearly polarized light, the orbital symmetry and dispersion of the surface localized electronic states have been unambiguously determined. The quantum well states (QWS) originating from the Ag orbitals are confined within the Ag overlayer, while the quantum well resonance states (QWRS) are hybridized with substrate Mo and S orbitals. The photon energy dependence of the dispersion characteristics confirms the two-dimensional (2D) nature of these quantum states while their momentum dependence is a consequence of the finite lateral coherence length of the electrons. Our ARPES experiments using incident circularly polarized light on (0001) surface show circular dichroism effects (CD-ARPES), similar to recent studies where it is used to probe the initial state orbital angular momentum or the Berry curvature. While the QWS on the Ag overlayer does not exhibit any intensity asymmetry with the helicity of the incident light, the Ag QWRS show circular dichroism characteristics. The observed circular dichroism from the QWRS is attributed to the hybridization of these quantum states to the substrate states. We compare our ARPES results with the calculated orbital projected band structure to obtain a microscopic insight into the electronic behavior, which is critically important for manipulating wave functions for potential device applications.- 22 December 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 106 (23) , 235146
Polarization-dependent electronic structure of Ag quantum well states on the (0001) surface using ARPES and DFT studiesThe electronic band structure of clean and Ag-induced quantum well states on the (0001) surface has been investigated using polarization-dependent angle-resolved photoemission spectroscopy (ARPES) along with first-principle-based density functional theory (DFT) calculations. Using selective linearly polarized light, the orbital symmetry and dispersion of the surface localized electronic states have been unambiguously determined. The quantum well states (QWS) originating from the Ag orbitals are confined within the Ag overlayer, while the quantum well resonance states (QWRS) are hybridized with substrate Mo and S orbitals. The photon energy dependence of the dispersion characteristics confirms the two-dimensional (2D) nature of these quantum states while their momentum dependence is a consequence of the finite lateral coherence length of the electrons. Our ARPES experiments using incident circularly polarized light on (0001) surface show circular dichroism effects (CD-ARPES), similar to recent studies where it is used to probe the initial state orbital angular momentum or the Berry curvature. While the QWS on the Ag overlayer does not exhibit any intensity asymmetry with the helicity of the incident light, the Ag QWRS show circular dichroism characteristics. The observed circular dichroism from the QWRS is attributed to the hybridization of these quantum states to the substrate states. We compare our ARPES results with the calculated orbital projected band structure to obtain a microscopic insight into the electronic behavior, which is critically important for manipulating wave functions for potential device applications.