391 citations · 1.3k across the 29 of their papers we have counts for
29 papers
Angle-Resolved Pair Photoemission Theory for Correlated Electrons
Thomas P. Devereaux, Martin Claassen, Xu-Xin Huang +6
In this paper we consider the possibility and conditions for pair photoemission whereby two incident photons emit pairs of electrons from a candidate material as a novel method to…
Anharmonic multiphonon origin of the valence plasmon in SrTi1-xNbxO3
Caitlin S. Kengle, Samantha I. Rubeck, Melinda Rak +10
Doped SrTi1-xNbxO3 exhibits superconductivity and a mid-infrared optical response reminiscent of copper-oxide superconductors. Strangely, its plasma frequency, omega_p, increases b…
Observation of the massive Lee-Fukuyama phason in a charge density wave insulator
Soyeun Kim, Yinchuan Lv, Xiao-Qi Sun +10
The lowest-lying fundamental excitation of an incommensurate charge density wave (CDW) material is widely believed to be a massless phason -- a collective modulation of the phase o…
Two-electron photoemission spectroscopy in Topological Superconductors
Ka Ho Wong, Ameya Patwardhan, Peter Abbamonte +2
We demonstrate that the photo-electron counting rate, , measured in two electron coincidence spectroscopy (2-ARPES) experiments, provides unprecedented insight into the…
Ultrafast x-ray scattering reveals composite amplitude collective mode in the Weyl charge density wave material (TaSe)I
Quynh L. Nguyen, Ryan A. Duncan, Gal Orenstein +27
We report ultrafast x-ray scattering experiments of the quasi-1D charge density wave (CDW) material (TaSe)I following photoexcitation with femtosecond infrared laser pulses…
Spin-Resolved Topology and Partial Axion Angles in Three-Dimensional Insulators
Kuan-Sen Lin, Giandomenico Palumbo, Zhaopeng Guo +8
Symmetry-protected topological crystalline insulators (TCIs) have primarily been characterized by their gapless boundary states. However, in time-reversal- (-) invaria…
Band Structure Driven Thermoelectric Response of Topological Semiconductor ZrTe
Junbo Zhu, Changmin Lee, Fahad Mahmood +4
We report a transport, thermodynamic, and spectroscopic study of the recently identified topological semiconductor ZrTe with a focus on elucidating the connections between its…
Anomalous high-temperature THz nonlinearity in superconductors near the metal-insulator transition
Dipanjan Chaudhuri, David Barbalas, Ralph Romero +5
The interplay of strong disorder and superconductivity is a topic of long-term interest in condensed matter physics. Here we explore the nonlinear THz response of superconducting N…
Transport and optical properties of the chiral semiconductor Ag3AuSe2
Juyeon Won, Soyeun Kim, Martin Gutierrez-Amigo +9
Previous band structure calculations predicted Ag3AuSe2 to be a semiconductor with a band gap of approximately 1 eV. Here, we report single crystal growth of Ag3AuSe2 and its trans…
Effect of radiation-induced defects on the superfluid density and optical conductivity of overdoped LaSrCuO
Fahad Mahmood, David Ingram, Xi He +3
Using a combination of time-domain THz spectroscopy (TDTS) and mutual inductance measurements, we have investigated the low-energy electrodynamic response of overdoped LaSr…
Kramers-Weyl fermions in the chiral charge density wave material (TaSe)I
Soyeun Kim, Robert C. McKay, Nina Bielinski +11
The quasi-one-dimensional chiral charge density wave (CDW) material (TaSe)I has been recently predicted to host Kramers-Weyl (KW) fermions which should exist in the vicinit…
Distinguishing finite momentum superconducting pairing states with two-electron photoemission spectroscopy
Fahad Mahmood, Thomas Devereaux, Peter Abbamonte +1
We show theoretically that double photoemission (2-ARPES) may be used to identify the pairing state in superconductors in which the Cooper pairs have a nonzero center-of-mass mo…
BCS -wave behavior in the THz electrodynamic response of electron-doped cuprate superconductors
Zhenisbek Tagay, Fahad Mahmood, Anaelle Legros +3
Although cuprate superconductors have been intensively studied for the past decades, there is no consensus regarding the microscopic origin of their superconductivity. In this work…
The Future of the Correlated Electron Problem
A. Alexandradinata, N. P. Armitage, Andrey Baydin +44
A central problem in modern condensed matter physics is the understanding of materials with strong electron correlations. Despite extensive work, the essential physics of many of t…
Observation of a marginal Fermi glass using THz 2D coherent spectroscopy
Fahad Mahmood, Dipanjan Chaudhuri, Sarang Gopalakrishnan +2
A longstanding open problem in condensed matter physics is whether or not a strongly disordered interacting insulator can be mapped to a system of effectively non-interacting local…
Probing magnon dynamics and interactions in a ferromagnetic spin-1 chain
Prashant Chauhan, Fahad Mahmood, Hitesh J. Changlani +2
NiNbO is an almost ideal realization of a 1D spin-1 ferromagnetic Heisenberg chain compound with weak unidirectional anisotropy. Using time-domain THz spectroscopy, we…
Nodeless bulk superconductivity in the time-reversal symmetry breaking Bi/Ni bilayer system
Prashant Chauhan, Fahad Mahmood, Di Yue +3
Epitaxial bilayer films of Bi(110) and Ni host a time-reversal symmetry (TRS) breaking superconducting order with an unexpectedly high transition temperature K. Using t…
Locating the missing superconducting electrons in overdoped cuprates
Fahad Mahmood, Xi He, Ivan Bozovic +1
Overdoped high-temperature cuprate superconductors have been widely believed to be described by the physics of d-wave BCS-like superconductivity. However, recent measurements indic…
Observation of exciton-exciton interaction mediated valley depolarization in monolayer MoSe
Fahad Mahmood, Zhanybek Alpichshev, Yi-Hsien Lee +2
The valley pseudospin in monolayer transition metal dichalcogenides (TMDs) has been proposed as a new way to manipulate information in various optoelectronic devices. This relies o…
Hierarchy of exchange interactions in the triangular-lattice spin-liquid YbMgGaO
Xinshu Zhang, Fahad Mahmood, Marcus Daum +7
The spin-1/2 triangular lattice antiferromagnet YbMgGaO has attracted recent attention as a quantum spin-liquid candidate with the possible presence of off-diagonal anisotrop…
The origin of exciton mass in a frustrated Mott insulator NaIrO
Zhanybek Alpichshev, Edbert J. Sie, Fahad Mahmood +2
We use a three-pulse ultrafast optical spectroscopy to study the relaxation processes in a frustrated Mott insulator NaIrO. By being able to independently produce the out-o…
The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors
J. P. Hinton, E. Thewalt, Z. Alpichshev +14
The condensation of an electron superfluid from a conventional metallic state at a critical temperature is described well by the BCS theory. In the underdoped copper-oxides,…
Ultrafast dynamics in the presence of antiferromagnetic correlations in electron-doped cuprate LaCeCuO
I. M. Vishik, F. Mahmood, Z. Alpichshev +3
We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate LaCeCuO (LCCO) with…
Selective scattering between Floquet-Bloch and Volkov states in a topological insulator
Fahad Mahmood, Ching-Kit Chan, Zhanybek Alpichshev +4
The coherent optical manipulation of solids is emerging as a promising way to engineer novel quantum states of matter. The strong time periodic potential of intense laser light can…