Publications (29)
Unveiling the superconducting mechanism of BaKBiO
C. H. P. Wen, H. C. Xu, Q. Yao +17
Bismuthates were the first family of oxide high-temperature superconductors, exhibiting superconducting transition temperatures (Tc) up to 32K, but the superconducting mechanism re…
Enhanced superconductivity and evidence for novel pairing in single-layer FeSe on SrTiO3 thin film under large tensile strain
R. Peng, X. P. Shen, X. Xie +9
Single-layer FeSe films with extremely expanded in-plane lattice constant of 3.99A are fabricated by epitaxially growing FeSe/Nb:SrTiO3/KTaO3 heterostructures, and studied by in si…
Direct observation of the bandwidth control Mott transition in the NiSSe multiband system
H. C. Xu, Y. Zhang, M. Xu +6
The bulk electronic structure of NiSSe is studied across the bandwidth-control Mott transition (BCMT) by soft X-ray angle-resolved photoemission spectroscopy. The micro…
Direct evidence of superconductivity and determination of the superfluid density in buried ultrathin FeSe grown on SrTiO
P. K. Biswas, Z. Salman, Q. Song +6
Bulk FeSe is superconducting with a critical temperature 8 K and SrTiO is insulating in nature, yet high-temperature superconductivity has been reported at the in…
Colossal band renormalization and stoner ferromagnetism induced by electron-antiferromagnetic-magnon coupling
T. L. Yu, R. Peng, 2 M. Xu +15
The interactions between electrons and antiferromagnetic magnons (AFMMs) are important for a large class of correlated materials. For example, they are the most plausible pairing g…
Direct observation of how the heavy fermion state develops in CeCoIn5
Q. Y. Chen, D. F. Xu, X. H. Niu +19
Heavy fermion materials gain high electronic masses and expand Fermi surfaces when the high-temperature localized f electrons become itinerant and hybridize with the conduction ban…
Temperature-induced band selective localization and coherent-incoherent crossover in single-layer FeSe/Nb:BaTiO3 /KTaO3
Y. J. Pu, Z. C. Huang, H. C. Xu +5
Iron chalcogenide superconductors are multi-band systems with strong electron correlations. Here we use angle-resolved photoemission spectroscopy to study band dependent correlatio…
Plain s-wave superconductivity in single-layer FeSe on SrTiO3 probed by scanning tunneling microscopy
Q. Fan, W. H. Zhang, X. Liu +8
Single-layer FeSe film on SrTiO3(001) was recently found to be the champion of interfacial superconducting systems, with a much enhanced superconductivity than the bulk iron-based…
First Astronomical Detection of the Cumulene Carbon Chain Molecule H_2C_6 in TMC1
W. D. Langer, T. Velusamy, T. B. H. Kuiper +6
The cumulene carbenes are important components of hydrocarbon chemistry in low mass star forming cores. Here we report the first astronomical detection of the long chain cumulene c…
Anomalous correlation effects and unique phase diagram of electron doped FeSe revealed by angle resolved photoemission spectroscopy
C. H. P. Wen, H. C. Xu, C. Chen +9
In FeSe-derived superconductors, the lack of a systematic and clean control on the carrier concentration prevents the comprehensive understanding on the phase diagram and the inter…
Superconductivity across Lifshitz transition and anomalous insulating state in surface K-dosed (Li0.8Fe0.2OH)FeSe
M. Q. Ren, Y. J. Yan, X. H. Niu +7
In the iron-based superconductors, understanding the relation between superconductivity and electronic structure upon doping is crucial for exploring the pairing mechanism. Recentl…
Angle-resolved photoemission evidence of s-wave superconducting gap in KxFe2-ySe2 superconductor
M. Xu, Q. Q. Ge, R. Peng +7
Although nodeless superconducting gap has been observed on the large Fermi pockets around the zone corner in KxFe2-ySe2, whether its pairing symmetry is s-wave or nodeless d-wave i…
Electronic structure and 4f-electron character in Ce2PdIn8 studied by angle-resolved photoemission spectroscopy
Q. Yao, D. Kaczorowski, P. Swatek +10
The localized-to-itinerant transition of f electrons lies at the heart of heavy-fermion physics, but has only been directly observed in single-layer Ce-based materials. Here, we re…
Band dependent inter-layer -electron hybridization in CeRhIn
Q. Y. Chen, D. F. Xu, X. H. Niu +16
A key issue in heavy fermion research is how subtle changes in the hybridization between the 4 (5) and conduction electrons can result in fundamentally different ground state…
Dichotomy in the Dynamical Status of Massive Cores in Orion
T. velusamy, R. Peng, D. Li +2
To study the evolution of high mass cores, we have searched for evidence of collapse motions in a large sample of starless cores in the Orion molecular cloud. We used the Caltech S…
Electronic structure of the BaTiAsO parent compound of the titanium based oxypnictide superconductor
H. C. Xu, M. Xu, R. Peng +12
The electronic structure of BaTi2As2O, a parent compound of the newly discovered titanium-based oxypnictide superconductors, is studied by angle-resolved photoemission spectroscopy…
The origin of the dead-layer at the La0.67Sr0.33MnO3/SrTiO3 interface and dead-layer reduction via interfacial engineering
R. Peng, H. C. Xu, M. Xia +5
Transition metal oxide hetero-structure has great potential for multifunctional devices. However, the degraded physical properties at interface, known as dead-layer behavior, prese…
Distinct Kondo Screening Behaviors in Heavy Fermion Filled Skutterudites with 4f1 and 4f2 Configurations
X. Lou, H. C. Xu, T. L. Yu +9
Filled-skutterudite heavy fermion (HF) compounds host rich ground states depending on the f electron configurations. CeOs4Sb12 (COS) with Ce 4f1, and PrOs4Sb12 (POS) with Pr 4f2 co…
Robust and clean Majorana zero mode in the vortex core of high-temperature superconductor (Li0.84Fe0.16)OHFeSe
Q. Liu, C. Chen, T. Zhang +13
The Majorana fermion, which is its own anti-particle and obeys non-abelian statistics, plays a critical role in topological quantum computing. It can be realized as a bound state a…
Highly anisotropic and two-fold symmetric superconducting gap in nematically ordered FeSeS
H. C. Xu, X. H. Niu, D. F. Xu +7
FeSe exhibits a novel ground state in which superconductivity coexists with a nematic order in the absence of any long-range magnetic order. Here we report an angle-resolved photoe…
Surface electronic structure and isotropic superconducting gap in (LiFe)OHFeSe
X. H. Niu, R. Peng, H. C. Xu +13
Using angle-resolved photoemission spectroscopy (ARPES), we revealed the surface electronic structure and superconducting gap of (LiFe)OHFeSe, an intercalated FeSe-…
Critical role of substrate in the high temperature superconductivity of single layer FeSe on Nb:BaTiO
R. Peng, H. C. Xu, S. Y. Tan +8
In the quest for high temperature superconductors, the interface between a metal and a dielectric was proposed to possibly achieve very high superconducting transition temperature…
Discovery of Hydrogen Fluoride in the Cloverleaf Quasar at z = 2.56
R. R. Monje, T. G. Phillips, R. Peng +3
We report the first detection of hydrogen fluoride (HF) toward a high redshift quasar. Using the Caltech Submillimeter Observatory (CSO) we detect the HF J = 1 - 0 transition in ab…
Simultaneous Determination of the Cosmic Ray Ionization Rate and Fractional Ionization in DR21(OH)
T. Hezareh, M. Houde, C. McCoey +2
We present a new method for the simultaneous calculation of the cosmic ray ionization rate, zeta(H2), and the ionization fraction, chi(e), in dense molecular clouds. A simple netwo…
Phonon-enhanced superconductivity at the FeSe/SrTiO3 interface
Q. Song, T. L. Yu, X. Lou +9
The dream of room temperature superconductors has inspired intense research effort to find routes for enhancing the superconducting transition temperature (Tc). Therefore, single-l…
Interface-induced superconductivity and strain-dependent spin density wave in FeSe/SrTiO3 thin films
S. Y. Tan, M. Xia, Y. Zhang +14
The record of superconducting transition temperature(Tc) has long been 56K for the iron-based high temperature superconductors(Fe-HTS's). Recently, in single layer FeSe films grown…
Electronic Structure Reconstruction across the Antiferromagnetic Transition in TaFeTe Spin Ladder
M. Xu, Li-Min Wang, R. Peng +19
With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFeTe, which is a two-leg spin ladder compound with a novel antiferromagnetic g…
Evolution of spin excitations from bulk to monolayer FeSe
J. Pelliciari, S. Karakuzu, Q. Song +17
The discovery of enhanced superconductivity (SC) in FeSe films grown on SrTiO3 (FeSe/STO) has revitalized the field of Fe-based superconductors. In the ultrathin limit, the superco…
Cuprate-like Electronic Structures in Infinite-Layer Nickelates with Substantial Hole Dopings
X. Ding, Y. Fan, X. X. Wang +13
The superconducting infinite-layer (IL) nickelates offer a new platform for investigating the long-standing problem of high-temperature superconductivity. Many models were proposed…