Pawel Starowicz
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
Pawel Starowicz has a total of 130 co-authors. Here are the top co-authors by number of shared publications:
A. Szytuła
10 shared publications- Rafal Kurleto
National Synchrotron Radiation Centre SOLARIS
10 shared publications - Jerzy Goraus
University of Silesia
9 shared publications - Marcin Rosmus
Jagiellonian University
6 shared publications J. Goraus
Institute of Physics University of Silesia 75 Pu lku Piechoty 1a 41-500 Chorzów Poland
5 shared publicationsB. Penc
M. Smoluchowski Institute of Physics, Jagiellonian University, S. Łojasiewicza 11, 30-348 Kraków, Poland
4 shared publications
Latest Publications
- Open Access
- 15 May 2026
- Published by Jagiellonian University in Acta Physica Polonica B
- Vol. 57 (5)
Hybridization Effects in CeCoIn\(_5\) Studied by Angle-resolved Photoemission SpectroscopyWe studied the electronic structure of a canonical heavy fermion superconductor CeCoIn\(_5\) using angle-resolved photoelectron spectroscopy (ARPES). We observed a non-uniform distribution of \(4f\)-derived spectral weight across the Fermi surface map measured below the coherence temperature (\(T=6~\mathrm {K} \lt T_\mathrm {coh}\approx 45\) K). Different effects of the coupling between \(4f\)-states and conduction bands were observed near the Fermi level (\(E_\mathrm {F}\)): (i) rapid change of the band slope and increasing \(4f\) spectral contribution, when approaching \(E_\mathrm {F}\), (ii) presence of heavy quasiparticle bands (\(m^{\star }\sim 100m_e\)). Published by the Jagiellonian University 2026 authors- 15 May 2026
- Published by Jagiellonian University in Acta Physica Polonica B
- Vol. 57 (5)
Open AccessHybridization Effects in CeCoIn\(_5\) Studied by Angle-resolved Photoemission SpectroscopyWe studied the electronic structure of a canonical heavy fermion superconductor CeCoIn\(_5\) using angle-resolved photoelectron spectroscopy (ARPES). We observed a non-uniform distribution of \(4f\)-derived spectral weight across the Fermi surface map measured below the coherence temperature (\(T=6~\mathrm {K} \lt T_\mathrm {coh}\approx 45\) K). Different effects of the coupling between \(4f\)-states and conduction bands were observed near the Fermi level (\(E_\mathrm {F}\)): (i) rapid change of the band slope and increasing \(4f\) spectral contribution, when approaching \(E_\mathrm {F}\), (ii) presence of heavy quasiparticle bands (\(m^{\star }\sim 100m_e\)). Published by the Jagiellonian University 2026 authors - Open Access
Observation of the Dirac Dispersions in Co-doped CaFe2As2
We performed an angle-resolved photoemission spectroscopy (ARPES) study of the electronic structure of the CaFe$_2$As$_2$ 122-iron pnictide, a parent compound, and two iron-based superconductors CaFe$_{2-x}$Co$_x$As$_2$ ($x = 0.07$ and 0.15). We studied the band structure of this system across the phase diagram with the transition from the orthorhombic spin density wave (SDW) phase to the tetragonal paramagnetic phase. We observed characteristic features of the electronic structures corresponding to the antiferromagnetic phase in the parent compound and the samples with low cobalt concentration ($x = 0.07$). For highly doped systems ($x = 0.15$), the measurements revealed the concentric branches of the Fermi surface, which are associated with paramagnetic and superconducting 122-iron pnictides. We found the existence of Dirac cones located at 30 meV below Fermi energy for nonsuperconducting CaFe$_2$As$_2$ and superconducting CaFe$_{1.93}$Co$_{0.07}$As$_2$ orthorhombic SDW systems.
Open AccessObservation of the Dirac Dispersions in Co-doped CaFe2As2
We performed an angle-resolved photoemission spectroscopy (ARPES) study of the electronic structure of the CaFe$_2$As$_2$ 122-iron pnictide, a parent compound, and two iron-based superconductors CaFe$_{2-x}$Co$_x$As$_2$ ($x = 0.07$ and 0.15). We studied the band structure of this system across the phase diagram with the transition from the orthorhombic spin density wave (SDW) phase to the tetragonal paramagnetic phase. We observed characteristic features of the electronic structures corresponding to the antiferromagnetic phase in the parent compound and the samples with low cobalt concentration ($x = 0.07$). For highly doped systems ($x = 0.15$), the measurements revealed the concentric branches of the Fermi surface, which are associated with paramagnetic and superconducting 122-iron pnictides. We found the existence of Dirac cones located at 30 meV below Fermi energy for nonsuperconducting CaFe$_2$As$_2$ and superconducting CaFe$_{1.93}$Co$_{0.07}$As$_2$ orthorhombic SDW systems.
- 24 June 2024
- Published by Elsevier in Journal of Alloys and Compounds
- Vol. 1002
Dirac dispersions and Fermi surface nesting in LaCuSb2
- 24 June 2024
- Published by Elsevier in Journal of Alloys and Compounds
- Vol. 1002
Dirac dispersions and Fermi surface nesting in LaCuSb2
- Open Access
Dirac Dispersions and Fermi Surface Nesting in LaCuSb$_{2}$
LaCuSb$_{2}$ is a superconductor with a transition temperature of about $T_\text{c} = 0.9$K and is a potential platform where Dirac fermions can be experimentally observed. In this paper, we report systematic high-resolution studies of its electronic structure using the angle-resolved photoemission spectroscopy (ARPES) technique supported by the DFT calculation. The Fermi surface consists of four branches, of which the two inner ones are more 3-dimensional and the theoretical calculations reproduce well the experiment. We observe several linear dispersions forming Dirac-like structures. The nodal lines are present in the system along ${\text{M}}$-${\text{A}}$ and ${\text{X}}$-${\text{R}}$ and Dirac crossings along ${\text{X}}$-${\text{R}}$ are observed by ARPES. Finally, the nesting between external Fermi surface pockets, which corresponds to charge density wave (CDW) modulation vector is enhanced in LaCuSb$_{2}$ as compared to LaAgSb$_{2}$, while CDW appears in the latter system.Open AccessDirac Dispersions and Fermi Surface Nesting in LaCuSb$_{2}$
LaCuSb$_{2}$ is a superconductor with a transition temperature of about $T_\text{c} = 0.9$K and is a potential platform where Dirac fermions can be experimentally observed. In this paper, we report systematic high-resolution studies of its electronic structure using the angle-resolved photoemission spectroscopy (ARPES) technique supported by the DFT calculation. The Fermi surface consists of four branches, of which the two inner ones are more 3-dimensional and the theoretical calculations reproduce well the experiment. We observe several linear dispersions forming Dirac-like structures. The nodal lines are present in the system along ${\text{M}}$-${\text{A}}$ and ${\text{X}}$-${\text{R}}$ and Dirac crossings along ${\text{X}}$-${\text{R}}$ are observed by ARPES. Finally, the nesting between external Fermi surface pockets, which corresponds to charge density wave (CDW) modulation vector is enhanced in LaCuSb$_{2}$ as compared to LaAgSb$_{2}$, while CDW appears in the latter system. - Open Access
Electronic Band Structure and Surface States in Dirac Semimetal LaAgSb2
LaAgSb is a Dirac semimetal showing charge density wave (CDW) order. Previous angle-resolved photoemission spectroscopy (ARPES) results suggest the existence of the Dirac-cone-like structure in the vicinity of the Fermi level along the –M direction. This paper is devoted to a complex analysis of the electronic band structure of LaAgSb by means of ARPES and theoretical studies within the ab initio method as well as tight binding model formulation. To investigate the possible surface states, we performed the direct DFT slab calculation and the surface Green function calculation for the (001) surface. The appearance of the surface states, which depends strongly on the surface, points to the conclusion that LaSb termination is realized in the cleaved crystals. Moreover, the surface states predicted by our calculations at the and X points are found by ARPES. Nodal lines, which exist along the X–R and M–A paths due to crystal symmetry, are also observed experimentally. The calculations reveal other nodal lines, which originate from the vanishing of spin–orbit splitting and are located at the X–M–A–R plane at the Brillouin zone boundary. In addition, we analyze the band structure along the –M path to verify whether Dirac surface states can be expected. Their appearance in this region is not confirmed.Open AccessElectronic Band Structure and Surface States in Dirac Semimetal LaAgSb2
LaAgSb is a Dirac semimetal showing charge density wave (CDW) order. Previous angle-resolved photoemission spectroscopy (ARPES) results suggest the existence of the Dirac-cone-like structure in the vicinity of the Fermi level along the –M direction. This paper is devoted to a complex analysis of the electronic band structure of LaAgSb by means of ARPES and theoretical studies within the ab initio method as well as tight binding model formulation. To investigate the possible surface states, we performed the direct DFT slab calculation and the surface Green function calculation for the (001) surface. The appearance of the surface states, which depends strongly on the surface, points to the conclusion that LaSb termination is realized in the cleaved crystals. Moreover, the surface states predicted by our calculations at the and X points are found by ARPES. Nodal lines, which exist along the X–R and M–A paths due to crystal symmetry, are also observed experimentally. The calculations reveal other nodal lines, which originate from the vanishing of spin–orbit splitting and are located at the X–M–A–R plane at the Brillouin zone boundary. In addition, we analyze the band structure along the –M path to verify whether Dirac surface states can be expected. Their appearance in this region is not confirmed. - 2 September 2021
- Published by American Physical Society (APS) in Physical Review B
- Vol. 104 (12) , 125104
Photoemission signature of momentum-dependent hybridization inHybridization between electrons and conduction bands (c-f hybridization) is a driving force for many unusual phenomena. To provide insight into it, systematic studies of heavy fermion superconductor have been performed by angle-resolved photoemission spectroscopy (ARPES) in a large angular range at temperature of K. The used photon energy of 122 eV corresponds to Ce resonance. Calculations carried out with the relativistic multiple scattering Korringa-Kohn-Rostoker method and one-step model of photoemission yielded realistic simulation of the ARPES spectra, indicating that Ce-In surface termination prevails. Surface states, which have been identified in the calculations, contribute significantly to the spectra. Effects of the hybridization strongly depend on wave vector. They include a dispersion of heavy electrons and bands gaining -electron character when approaching Fermi energy. We have also observed a considerable variation of -electron spectral weight at , which is normally determined by both matrix element effects and wave vector dependent c-f hybridization. Fermi surface scans covering a few Brillouin zones revealed large matrix element effects. A symmetrization of experimental Fermi surface, which reduces matrix element contribution, yielded a specific variation of -electron enhanced spectral intensity at around and points. Tight-binding approximation calculations for Ce-In plane provided the same universal distribution of -electron density for a range of values of the parameters used in the model.- 2 September 2021
- Published by American Physical Society (APS) in Physical Review B
- Vol. 104 (12) , 125104
Photoemission signature of momentum-dependent hybridization inHybridization between electrons and conduction bands (c-f hybridization) is a driving force for many unusual phenomena. To provide insight into it, systematic studies of heavy fermion superconductor have been performed by angle-resolved photoemission spectroscopy (ARPES) in a large angular range at temperature of K. The used photon energy of 122 eV corresponds to Ce resonance. Calculations carried out with the relativistic multiple scattering Korringa-Kohn-Rostoker method and one-step model of photoemission yielded realistic simulation of the ARPES spectra, indicating that Ce-In surface termination prevails. Surface states, which have been identified in the calculations, contribute significantly to the spectra. Effects of the hybridization strongly depend on wave vector. They include a dispersion of heavy electrons and bands gaining -electron character when approaching Fermi energy. We have also observed a considerable variation of -electron spectral weight at , which is normally determined by both matrix element effects and wave vector dependent c-f hybridization. Fermi surface scans covering a few Brillouin zones revealed large matrix element effects. A symmetrization of experimental Fermi surface, which reduces matrix element contribution, yielded a specific variation of -electron enhanced spectral intensity at around and points. Tight-binding approximation calculations for Ce-In plane provided the same universal distribution of -electron density for a range of values of the parameters used in the model.- Open Access
Kondo Lattice Behavior Observed in the CeCu$_9$In$_2$ Compound
We report systematic studies of CeCu$_9$In$_2$, which appears to be a new Kondo lattice system. Electrical resistivity exhibits a logarithmic law characteristic of Kondo systems with a broad maximum at $T_{coh}\approx$45 K and it obeys the Fermi liquid theory at low temperature. Specific heat of CeCu$_9$In$_2$ is well described by the Einstein and Debye models with electronic part at high temperature. Fitting of the Schottky formula to low temperature 4f contribution to specific heat yielded crystal field splitting of 50.2 K between a doublet and quasi-quartet. The Schotte-Schotte model estimates roughly Kondo temperature as $T_K\approx$5 K, but does not reproduce well the data due to a sharp peak at 1.6 K. This structure should be attributed to a phase transition, a nature of which is possibly antiferromagnetic. Specific heat is characterized with increased Sommerfeld coefficient estimated as $\gamma\approx$132 mJ/(mole$\cdot$K$^2$). Spectra of the valence band, which have been collected with ultraviolet photoelectron spectroscopy (UPS), show a peak at binding energy$\approx$250 meV, which originates from the Ce 4f electrons and is related to the 4f$^1$$_{7/2}$ final state. Extracted 4f contribution to the spectral function exhibits also the enhancement of intensity in the vicinity of the Fermi level. Satellite structure of the Ce 3d levels spectra measured by X-ray photoelectron spectroscopy (XPS) has been analyzed within the framework of the Gunnarsson-Sch\"onhammer theory. Theoretical calculations based on density functional theory (FPLO method with LDA+U approach) delivered densities of states, band structures and Fermi surfaces for CeCu$_9$In$_2$ and LaCu$_9$In$_2$. The results indicate that Fermi surface nesting takes place in CeCu$_9$In$_2$.Open AccessKondo Lattice Behavior Observed in the CeCu$_9$In$_2$ Compound
We report systematic studies of CeCu$_9$In$_2$, which appears to be a new Kondo lattice system. Electrical resistivity exhibits a logarithmic law characteristic of Kondo systems with a broad maximum at $T_{coh}\approx$45 K and it obeys the Fermi liquid theory at low temperature. Specific heat of CeCu$_9$In$_2$ is well described by the Einstein and Debye models with electronic part at high temperature. Fitting of the Schottky formula to low temperature 4f contribution to specific heat yielded crystal field splitting of 50.2 K between a doublet and quasi-quartet. The Schotte-Schotte model estimates roughly Kondo temperature as $T_K\approx$5 K, but does not reproduce well the data due to a sharp peak at 1.6 K. This structure should be attributed to a phase transition, a nature of which is possibly antiferromagnetic. Specific heat is characterized with increased Sommerfeld coefficient estimated as $\gamma\approx$132 mJ/(mole$\cdot$K$^2$). Spectra of the valence band, which have been collected with ultraviolet photoelectron spectroscopy (UPS), show a peak at binding energy$\approx$250 meV, which originates from the Ce 4f electrons and is related to the 4f$^1$$_{7/2}$ final state. Extracted 4f contribution to the spectral function exhibits also the enhancement of intensity in the vicinity of the Fermi level. Satellite structure of the Ce 3d levels spectra measured by X-ray photoelectron spectroscopy (XPS) has been analyzed within the framework of the Gunnarsson-Sch\"onhammer theory. Theoretical calculations based on density functional theory (FPLO method with LDA+U approach) delivered densities of states, band structures and Fermi surfaces for CeCu$_9$In$_2$ and LaCu$_9$In$_2$. The results indicate that Fermi surface nesting takes place in CeCu$_9$In$_2$. - Open Access
Effect of electron doping in FeTe$_{1-y}$Se$_{y}$ realized by Co and Ni substitution
Angle-resolved photoemission spectroscopy (ARPES) reveals effects of electron doping, which is realized by Co and Ni substitution for Fe in FeTe$_{1-y}$Se$_{y}$ (y$\sim$0.35) superconductor. The data show consistent band shifts as well as expansion and shrinking of electron and hole Fermi surface, respectively. Doping of either element leads to a Lifshitz transition realized as a removal of one or two hole pockets. This explains qualitatively a complex behavior of Hall coefficient observed before [Bezusyy, et al., Phys. Rev. B 91, 100502 (2015)], including change of sign with doping, which takes place only below room temperature. Assuming that Ni substitution should deliver twice more electrons to the valence band than Co, it appears that such transfer is slightly more effective in the case of Co. Therefore, charge doping cannot account for much stronger effect of Ni on superconducting and transport properties [Bezusyy, et al., Phys. Rev. B 91, 100502 (2015)]. Although overall band shifts are roughly proportional to the amount of dopant, clear deviations from a rigid band shift scenario are found. The shape of electron pockets becomes elliptical only for Ni doping, effective mass of electron bands increases with doping, strong reduction of effective mass is observed for one of hole bands of the undoped system. The topology of hole and electron pockets for superconducting Fe$_{1.01}$Te$_{0.67}$Se$_{0.33}$ with T$_{c}$=13.6 K indicates a deviation from nesting. Co and Ni doping causes further departure from nesting, which accompanies the reduction of critical temperature.
Open AccessEffect of electron doping in FeTe$_{1-y}$Se$_{y}$ realized by Co and Ni substitution
Angle-resolved photoemission spectroscopy (ARPES) reveals effects of electron doping, which is realized by Co and Ni substitution for Fe in FeTe$_{1-y}$Se$_{y}$ (y$\sim$0.35) superconductor. The data show consistent band shifts as well as expansion and shrinking of electron and hole Fermi surface, respectively. Doping of either element leads to a Lifshitz transition realized as a removal of one or two hole pockets. This explains qualitatively a complex behavior of Hall coefficient observed before [Bezusyy, et al., Phys. Rev. B 91, 100502 (2015)], including change of sign with doping, which takes place only below room temperature. Assuming that Ni substitution should deliver twice more electrons to the valence band than Co, it appears that such transfer is slightly more effective in the case of Co. Therefore, charge doping cannot account for much stronger effect of Ni on superconducting and transport properties [Bezusyy, et al., Phys. Rev. B 91, 100502 (2015)]. Although overall band shifts are roughly proportional to the amount of dopant, clear deviations from a rigid band shift scenario are found. The shape of electron pockets becomes elliptical only for Ni doping, effective mass of electron bands increases with doping, strong reduction of effective mass is observed for one of hole bands of the undoped system. The topology of hole and electron pockets for superconducting Fe$_{1.01}$Te$_{0.67}$Se$_{0.33}$ with T$_{c}$=13.6 K indicates a deviation from nesting. Co and Ni doping causes further departure from nesting, which accompanies the reduction of critical temperature.
- Open Access
- 2 September 2019
- Published by Springer Nature in The European Physical Journal B
- Vol. 92 (9) , 192
Studies of electronic structure across a quantum phase transition in CeRhSb1−xSnx
- 2 September 2019
- Published by Springer Nature in The European Physical Journal B
- Vol. 92 (9) , 192
Open AccessStudies of electronic structure across a quantum phase transition in CeRhSb1−xSnx
- 1 September 2019
- Published by Elsevier in Journal of Alloys and Compounds
- Vol. 803, 576-584
Kondo lattice behavior observed in the CeCu9In2 compound
- 1 September 2019
- Published by Elsevier in Journal of Alloys and Compounds
- Vol. 803, 576-584
Kondo lattice behavior observed in the CeCu9In2 compound