Dirac fermion relaxation and energy loss rate near the Fermi surface in monolayer and multilayer graphene

Nanoscale ◽  
2014 ◽  
Vol 6 (15) ◽  
pp. 8575-8578 ◽  
Author(s):  
C. W. Luo ◽  
P. S. Tseng ◽  
H.-J. Chen ◽  
K. H. Wu ◽  
L. J. Li
Keyword(s):  
Fermi Surface ◽  
Energy Loss ◽  
Loss Rate ◽  
Dirac Fermion ◽  
Ultrafast Dynamics ◽  
Multilayer Graphene ◽  
Dirac Fermions ◽  
Optical Pump ◽  
Mid Infrared ◽  
Probe Spectroscopy

Ultrafast dynamics of Dirac fermions near the Fermi surface in monolayer and multilayer graphene are revealed using optical pump mid-infrared probe spectroscopy.

Dirac Surface Plasmons in Photoexcited Bismuth Telluride Nanowires : Optical Pump-Terahertz Probe Spectroscopy

Nanoscale ◽  
2021 ◽  
Author(s):  
Mithun K P ◽  
Srabani Kar ◽  
Abinash Kumar ◽  
Victor Suvisesha Muthu Dharmaraj ◽  
Ravishankar Narayanan ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Bismuth Telluride ◽  
Topological Insulators ◽  
Collective Excitation ◽  
Optical Pump ◽  
Time Resolved ◽  
Mid Infrared ◽  
Plasmonic Materials ◽  
Probe Spectroscopy

Collective excitation of Dirac plasmons in graphene and topological insulators have opened new possibilities of tunable plasmonic materials ranging from THz to mid-infrared regions. Using time resolved Optical Pump -...

Ultrafast dynamics in pentacene and tetracene probed using optical pump-probe spectroscopy

2004 ◽  
Author(s):  
Verner K. Thorsmølle ◽  
R D. Averitt ◽  
J Demsar ◽  
X Chi ◽  
S Tretiak ◽  
...  
Keyword(s):  
Ultrafast Dynamics ◽  
Optical Pump ◽  
Pump Probe ◽  
Probe Spectroscopy

scholarly journals Study on ultrafast dynamics of low-temperature grown GaAs by optical pump and terahertz probe spectroscopy

2017 ◽  
Vol 66 (8) ◽  
pp. 087801
Author(s):  
Fan Zheng-Fu ◽  
Tan Zhi-Yong ◽  
Wan Wen-Jian ◽  
Xing Xiao ◽  
Lin Xian ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ultrafast Dynamics ◽  
Optical Pump ◽  
Probe Spectroscopy ◽  
Low Temperature Grown Gaas

scholarly journals Measurement of ultrafast dynamics of photoexcited carriers inβ-Ga2O3by two-color optical pump-probe spectroscopy

2018 ◽  
Vol 113 (25) ◽  
pp. 252102 ◽  
Author(s):  
Okan Koksal ◽  
Nicholas Tanen ◽  
Debdeep Jena ◽  
Huili (Grace) Xing ◽  
Farhan Rana
Keyword(s):  
Ultrafast Dynamics ◽  
Optical Pump ◽  
Pump Probe ◽  
Probe Spectroscopy

scholarly journals Universal Fermi-surface anisotropy renormalization for interacting Dirac fermions with long-range interactions

2019 ◽  
Vol 116 (52) ◽  
pp. 26431-26434 ◽  
Author(s):  
Jia Ning Leaw ◽  
Ho-Kin Tang ◽  
Maxim Trushin ◽  
Fakher F. Assaad ◽  
Shaffique Adam
Keyword(s):  
Fermi Surface ◽  
Long Range ◽  
Quantum Monte Carlo ◽  
Fermi Liquid ◽  
Dirac Fermion ◽  
Magic Angle ◽  
Dirac Fermions ◽  
Surface Anisotropy ◽  
Coulomb Interactions ◽  
Fermi Surface Anisotropy

Recent experimental [I. Joet al.,Phys. Rev. Lett.119, 016402 (2017)] and numerical [M. Ippoliti, S. D. Geraedts, R. N. Bhatt,Phys. Rev. B95, 201104 (2017)] evidence suggests an intriguing universal relationship between the Fermi surface anisotropy of the noninteracting parent 2-dimensional (2D) electron gas and the strongly correlated composite Fermi liquid formed in a strong magnetic field close to half-filling. Inspired by these observations, we explore more generally the question of anisotropy renormalization in interacting 2D Fermi systems. Using a recently developed [H. -K. Tanget al.,Science361, 570 (2018)] nonperturbative and numerically exact projective quantum Monte Carlo simulation as well as other numerical and analytic techniques, only for Dirac fermions with long-range Coulomb interactions do we find a universal square-root decrease of the Fermi-surface anisotropy. For theν=1/2composite Fermi liquid, this result is surprising since a Dirac fermion ground state was only recently proposed as an alternative to the usual Halperin–Lee–Read state. Our proposed universality can be tested in several anisotropic Dirac materials including graphene, topological insulators, organic conductors, and magic-angle twisted bilayer graphene.

scholarly journals Gauge-Theory Approach to Planar Doped Antiferromagnets and External Magnetic Fields

1998 ◽  
Vol 12 (07n08) ◽  
pp. 809-836 ◽  
Author(s):  
K. Farakos ◽  
N. E. Mavromatos
Keyword(s):  
Gauge Theory ◽  
Magnetic Fields ◽  
Fermi Surface ◽  
Dirac Fermion ◽  
Theory Approach ◽  
Dirac Fermions ◽  
Abelian Gauge ◽  
Planar Systems ◽  
Experimental Findings ◽  
D Wave

Within the framework of a relativistic non-Abelian gauge theory approach to the physics of spin–charge separation in doped quantum antiferromagnetic planar systems, proposed recently by the authors, we are examining here the effects of constant external magnetic fields on excitations about the superconducting state in the model. The electrically-charged Dirac fermions (holons), describing excitations about specific points on the fermi surface, e.g. those corresponding to the nodes of a d-wave superconducting gap in high-T c cuprates, condense, resulting in the opening of a Kosterlitz–Thouless–like gap (KT) at such nodes. This leads, in general, to a second superconducting phase transition, which occurs at low temperatures[Formula: see text], in addition to the high-T c superconductivity [Formula: see text] due to the bulk of the fermi surface for holons in a (d-wave) spin–charge separated superconductor. In the presence of strong external magnetic fields at the surface regions of the planar superconductor, in the direction perpendicular to the superconducting planes, these KT gaps appear to be enhanced. Our preliminary analysis, based on analytic Schwinger–Dyson treatments, seems to indicate that for an even number of Dirac fermion species, required in our model as a result of gauging a particle–hole SU(2) symmetry, Parity or Time Reversal violation does not necessarily occurs. Based on these considerations, we argue that recent experimental findings, concerning thermal conductivity plateaux of quasiparticles in planar high-T c cuprates in strong external magnetic fields, may indicate the presence of such KT gaps, caused by charged Dirac-fermion excitations in these materials, as suggested in the above model.

Limits of Charge Carrier Transport in Halide Perovskites Revealed by Optical-Pump Terahertz-Probe Spectroscopy

2019 ◽  
Author(s):  
Hannes Hempel ◽  
Andrei Petsiu ◽  
Martin Stolterfoht ◽  
Pascal Becker ◽  
Dieter Neher ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Transport ◽  
Charge Carrier Transport ◽  
Optical Pump ◽  
Halide Perovskites ◽  
Probe Spectroscopy

scholarly journals Aspects of quantum information in finite density field theory

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Lucas Daguerre ◽  
Raimel Medina ◽  
Mario Solís ◽  
Gonzalo Torroba
Keyword(s):  
Field Theory ◽  
Quantum Information ◽  
Mutual Information ◽  
Fermi Surface ◽  
Relative Entropy ◽  
Chemical Potential ◽  
Operator Product ◽  
Dirac Fermions ◽  
Long Distance ◽  
Finite Density

Abstract We study different aspects of quantum field theory at finite density using methods from quantum information theory. For simplicity we focus on massive Dirac fermions with nonzero chemical potential, and work in 1 + 1 space-time dimensions. Using the entanglement entropy on an interval, we construct an entropic c-function that is finite. Unlike what happens in Lorentz-invariant theories, this c-function exhibits a strong violation of monotonicity; it also encodes the creation of long-range entanglement from the Fermi surface. Motivated by previous works on lattice models, we next calculate numerically the Renyi entropies and find Friedel-type oscillations; these are understood in terms of a defect operator product expansion. Furthermore, we consider the mutual information as a measure of correlation functions between different regions. Using a long-distance expansion previously developed by Cardy, we argue that the mutual information detects Fermi surface correlations already at leading order in the expansion. We also analyze the relative entropy and its Renyi generalizations in order to distinguish states with different charge and/or mass. In particular, we show that states in different superselection sectors give rise to a super-extensive behavior in the relative entropy. Finally, we discuss possible extensions to interacting theories, and argue for the relevance of some of these measures for probing non-Fermi liquids.

Photocarriers dynamics in silicon wafer studied with optical-pump terahertz-probe spectroscopy

2012 ◽  
Vol 285 (20) ◽  
pp. 4102-4106 ◽  
Author(s):  
Gaofang Li ◽  
Dong Li ◽  
Zuanming Jin ◽  
Guohong Ma
Keyword(s):  
Silicon Wafer ◽  
Optical Pump ◽  
Probe Spectroscopy
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