TY - JOUR
T1 - Absence of metallicity in K-doped picene
T2 - Importance of electronic correlations
AU - Ruff, Andreas
AU - Sing, Michael
AU - Claessen, Ralph
AU - Lee, Hunpyo
AU - Tomić, Milan
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
PY - 2013/5/21
Y1 - 2013/5/21
N2 - Potassium-doped picene (Kxpicene) has recently been reported to be a superconductor at x=3 with critical temperatures up to 18 K. Here we study the electronic structure of K-doped picene films by photoelectron spectroscopy and ab initio density functional theory combined with dynamical mean-field theory (DFT+DMFT). Experimentally we observe that, except for spurious spectral weight due to the lack of a homogeneous chemical potential at low K concentrations (x≈1), the spectra always display a finite energy gap. This result is supported by our DFT+DMFT calculations which provide clear evidence that Kxpicene is a Mott insulator for integer doping concentrations x=1, 2, and 3. We discuss various scenarios to understand the discrepancies with previous reports of superconductivity and metallic behavior.
AB - Potassium-doped picene (Kxpicene) has recently been reported to be a superconductor at x=3 with critical temperatures up to 18 K. Here we study the electronic structure of K-doped picene films by photoelectron spectroscopy and ab initio density functional theory combined with dynamical mean-field theory (DFT+DMFT). Experimentally we observe that, except for spurious spectral weight due to the lack of a homogeneous chemical potential at low K concentrations (x≈1), the spectra always display a finite energy gap. This result is supported by our DFT+DMFT calculations which provide clear evidence that Kxpicene is a Mott insulator for integer doping concentrations x=1, 2, and 3. We discuss various scenarios to understand the discrepancies with previous reports of superconductivity and metallic behavior.
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U2 - 10.1103/PhysRevLett.110.216403
DO - 10.1103/PhysRevLett.110.216403
M3 - Article
AN - SCOPUS:84878069527
VL - 110
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 21
M1 - 216403
ER -