Strong Correlation Effects in Fullerene Molecules and Solids

Similar documents
arxiv:cond-mat/ v2 [cond-mat.str-el] 24 Feb 2006

Organic Conductors and Superconductors: signatures of electronic correlations Martin Dressel 1. Physikalisches Institut der Universität Stuttgart

Excitonic Condensation in Systems of Strongly Correlated Electrons. Jan Kuneš and Pavel Augustinský DFG FOR1346

The many forms of carbon

Electronic structure of correlated electron systems. Lecture 2

ANTIFERROMAGNETIC EXCHANGE AND SPIN-FLUCTUATION PAIRING IN CUPRATES

ORBITAL SELECTIVITY AND HUND S PHYSICS IN IRON-BASED SC. Laura Fanfarillo

The Gutzwiller Density Functional Theory

Magnetism and Superconductivity in Decorated Lattices

per unit cell Motif: Re at (0, 0, 0); 3O at ( 1 / 2, 0), (0, 0, 1 / 2 ) Re: 6 (octahedral coordination) O: 2 (linear coordination) ReO 6

ORBITAL SELECTIVITY AND HUND S PHYSICS IN IRON-BASED SC. Laura Fanfarillo

Quantum Cluster Methods (CPT/CDMFT)

A Twisted Ladder: Relating the Iron Superconductors and the High-Tc Cuprates

Cluster Extensions to the Dynamical Mean-Field Theory

Magnetism and Superconductivity on Depleted Lattices

Polarons in linear chains of fullerenes

Quantum spin systems - models and computational methods

Resonating Valence Bond point of view in Graphene

Angle-Resolved Two-Photon Photoemission of Mott Insulator

Physics 211B : Problem Set #0

Role of the Octahedra Rotation on the Electronic Structures of 4d Transition Metal Oxides

Carbon nanotubes and Graphene

arxiv:cond-mat/ v1 [cond-mat.str-el] 29 Mar 2005

DT I JAN S S"= = 11111'11 I HtI IBlIIIt g ~II. Report: ONR Grant N J Unclassified: For General Distribution LECTF

MOTTNESS AND STRONG COUPLING

Computational strongly correlated materials R. Torsten Clay Physics & Astronomy

Novel Magnetic Properties of Carbon Nanotubes. Abstract

Calculating Electronic Structure of Different Carbon Nanotubes and its Affect on Band Gap

Quantum-Criticality in the dissipative XY and Ashkin-Teller Model: Application to the Cuprates and SIT..

Carbon nanotubes: Models, correlations and the local density of states

Quasiparticle dynamics and interactions in non uniformly polarizable solids

Crystal Structure of Rb 4 C 60 and K 4 C 60 under Pressure

CHAPTER 6 CHIRALITY AND SIZE EFFECT IN SINGLE WALLED CARBON NANOTUBES

Diamond. There are four types of solid: -Hard Structure - Tetrahedral atomic arrangement. What hybrid state do you think the carbon has?

There are four types of solid:

Introduction to Density Functional Theory

Spin Superfluidity and Graphene in a Strong Magnetic Field

The Hubbard model in cold atoms and in the high-tc cuprates

CDW phase of TiSe 2. Young Il Joe. May 5, 2008

Introduction to Heisenberg model. Javier Junquera

Theory of carbon-based magnetism

2D Materials with Strong Spin-orbit Coupling: Topological and Electronic Transport Properties

University of Bristol. 1 Naval Research Laboratory 2 II. Physikalisches Institut, Universität zu Köln

Theoretical and experimental study of aromatic hydrocarbon superconductors

What's so unusual about high temperature superconductors? UBC 2005

The Oxford Solid State Basics

Electron Correlation

Anisotropic Magnetic Structures in Iron-Based Superconductors

FROM NODAL LIQUID TO NODAL INSULATOR

Effect of next-nearest-neighbour interaction on d x 2 y2-wave superconducting phase in 2D t-j model

Computational Approaches to Quantum Critical Phenomena ( ) ISSP. Fermion Simulations. July 31, Univ. Tokyo M. Imada.

Quantum simulations, adiabatic transformations,

Inelastic Electronic Transport in the Smallest Fullerene C 20 Bridge

The High T c Superconductors: BCS or Not BCS?

Magnetism in correlated-electron materials

Excitonic Condensation of Strongly Correlated Electrons. Jan Kuneš DFG FOR1346

THERMODYNAMIC PROPERTIES OF ONE-DIMENSIONAL HUBBARD MODEL AT FINITE TEMPERATURES

Supporting Information

Lecture 4: Band theory

Interaction-induced Symmetry Protected Topological Phase in Harper-Hofstadter models

Introduction to Nanotechnology Chapter 5 Carbon Nanostructures Lecture 1

Effect of dimensionality in polymeric fullerenes and single-wall nanotubes

Strongly Correlated Systems:

ELECTRONIC ENERGY DISPERSION AND STRUCTURAL PROPERTIES ON GRAPHENE AND CARBON NANOTUBES

Effects of spin-orbit coupling on the BKT transition and the vortexantivortex structure in 2D Fermi Gases

Luttinger Liquid at the Edge of a Graphene Vacuum

Berry s phase in Hall Effects and Topological Insulators

The electronic structure of materials 1

Superconductivity in Heavy Fermion Systems: Present Understanding and Recent Surprises. Gertrud Zwicknagl

Theoretical Study of High Temperature Superconductivity

Many-body excitations in undoped Graphene

Lattice modulation experiments with fermions in optical lattices and more

The Hubbard Model In Condensed Matter and AMO systems

High Tc superconductivity in cuprates: Determination of pairing interaction. Han-Yong Choi / SKKU SNU Colloquium May 30, 2018

COMPETITION BETWEEN FILLED AND HALF-FILLED STRIPES IN CUPRATES AND NICKELATES

ELEMENTARY BAND THEORY

The Mott Metal-Insulator Transition

Single Electron Tunneling Examples

ORIGINS. E.P. Wigner, Conference on Neutron Physics by Time of Flight, November 1956

Resonant Inelastic X-ray Scattering on elementary excitations

Magnetic Moment Collapse drives Mott transition in MnO

New Volleyballenes: Y 20 C 60, La 20 C 60, and Lu 20 C 60

Electronic structure of correlated electron systems. G.A.Sawatzky UBC Lecture

High-T c superconductors. Parent insulators Carrier doping Band structure and Fermi surface Pseudogap and superconducting gap Transport properties

Visualization of atomic-scale phenomena in superconductors

Luigi Paolasini

Density matrix renormalization group study of a three- orbital Hubbard model with spin- orbit coupling in one dimension

Spin and orbital freezing in unconventional superconductors

Degeneracy Breaking in Some Frustrated Magnets. Bangalore Mott Conference, July 2006

Zero-bias conductance peak in detached flakes of superconducting 2H-TaS2 probed by STS

Topological edge states in a high-temperature superconductor FeSe/SrTiO 3 (001) film

Quantum Choreography: Exotica inside Crystals

How to model holes doped into a cuprate layer

Electronic Squeezing by Optically Pumped Phonons: Transient Superconductivity in K 3 C 60. With: Eli Wilner Dante Kennes Andrew Millis

Initial Stages of Growth of Organic Semiconductors on Graphene

New perspectives in superconductors. E. Bascones Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC)

NiO - hole doping and bandstructure of charge transfer insulator

Let There Be Topological Superconductors

Tuning order in cuprate superconductors

ARPES studies of cuprates. Inna Vishik Physics 250 (Special topics: spectroscopies of quantum materials) UC Davis, Fall 2016

Transcription:

Strong Correlation Effects in Fullerene Molecules and Solids Fei Lin Physics Department, Virginia Tech, Blacksburg, VA 2461 Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 1 / 3

Collaborators: Erik Sorensen, McMaster University, Canada Catherine Kallin, McMaster University, Canada John Berlinsky, McMaster University and Perimeter Institute for Theoretical Physics, Canada Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 2 / 3

Outline: Introduction to Fullerene molecules and solids. Effective tight-binding Hubbard model for the molecules. C 2 molecule and solid: pair-binding energies; magnetic properties; density of states, etc. C 6 molecule and solid: Single-particle excitation spectrum for solid; molecular orientations; comparison with ARPES. Some recent experimental developments. Summary. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 3 / 3

Introduction Carbon based nano materials D: cage structures: C 6, C 2, etc. (Nobel Prize in 1996) 1D: rod structures: nanotube. 2D: planar sheet structure: graphene (Nobel prize 21) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 4 / 3

Introduction Intensive researches in the past 21, derivatives of fullerene found by the end of 22; 23, papers published by the end of 22; Amazing properties: superconducting, ferromagnetic, antiferromagnetic, spin density wave,... Crystal structures seems relatively simpler than cuprates; However, after 2 years research superconducting mechanism still unclear. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 5 / 3

Introduction. What are Fullerene molecules? Carbon cage molecules with exactly 12 pentagons and varying number of hexagons. A consequence of Euler s polyhedral formula: V E +F = 2. Three examples: C 2 : V = 2, E = 3, F = 12; C 36 : V = 36, E = 54, F = 2; C 6 : V = 6, E = 9, F = 32. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 6 / 3

Introduction. Synthesis and properties. C 6 discovered by Kroto, Curl, and Smalley [Nature, 1985] (Nobel Prize in 1996). K 3 C 6 molecular superconductor (Tc=18K) found by Hebard et al [Nature, 1991]. Pentagon separation rule, Kroto [Nobel lecture, 1997]. Solid C 36 first produced by Zettl group [Nature, 1998]. Gas phase C 2 first produced by Prinzbach et al [Nature, 2]. Solid C 2 synthesized by Wang et al [Phys. Lett. A, 21] and Iqbal et al [Eur. Phys. J. B, 23]. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 7 / 3

Outline: Introduction to Fullerene molecules and solids. Effective tight-binding Hubbard model for the molecules. C 2 molecule and solid: pair-binding energies; magnetic properties; density of states, etc. C 6 molecule and solid: Single-particle excitation spectrum for solid; molecular orientations; comparison with ARPES. Some recent experimental developments. Summary. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 8 / 3

Effective Hamiltonian Approach Importance of Carbon radial p r orbitals Fullerene molecules electronic properties are mainly determined by the electrons from Carbon atom radial p r orbitals. Eg. for C 6 molecule, 94% of bonds around Fermi energy are made of p r orbitals as shown by Satpathy [Chem. Phys. Lett., 1985]. Conjugated π bonds: electron delocalization One-band tight-binding Hamiltonian description can be successful. Effective Hamiltonian: Hubbard Model H = ij σ t ij (c iσ c jσ +h.c.)+u i n i n i, (1) What are U/t values? Solve by quantum Monte Carlo (QMC) and exact diagonalization (ED). Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 9 / 3

Effective Hamiltonian Approach Huckel energy level diagrams For U = (non-interacting), we can easily diagonalize Hamiltonian: Molecular Orbitals of C 6 3 2.65 2.41 C36 Molecular Orbitals 2 2. 1.73 1 Energy / t 2.24 2. 1. 2.24 3. C2 Molecular Orbitals T 2u Gg G u T1u Ag Hg Energy / t 1.56 1..41 1. 1.73 2. 2.56 2.65 3. LUMO HOMO Energy (t) 1 2 3 t 1g t 1u h u h g Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 1 / 3

Effective Hamiltonian Approach Huckel energy level diagrams: electron dopings Energy (t) 3 2 1 1 2 3 Molecular Orbitals of C 6 t 1g t 1u h u h g C 6 : quasi 1D lattice, phase transition at 5K from 1D conductor to spin density wave ground state; Chauvet et al [Phys. Rev. Lett. 1994], Stephens et al [Nature 1994]. C 2 6 : no; not yet realized. : yes; discuss this later. C 3 6 C 4 6 C 5 : insulator; Fleming et al [Nature 1991] 6 : metal monolayer; Crommie group [Science 25, Phys. Rev. Lett. 27] C 6 6 : insulator; Zhou et al [Nature 1991], Stephens et al [Phys. Rev. B 1992] Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 11 / 3

Effective Hamiltonian Approach Parameters Determination Hopping t ij can be determined by fitting Huckel energy levels around Fermi energy to those from DFT calculations. U can be determined by comparison to some experiments: Electron affinity energy Wang et al [J. Chem. Phys., 1999] for C 6 Prinzbach et al [Nature, 2] for C 2. X-ray scattering Chow and Friedman [Phys. Rev. B, 28] Dynamic structure factor: S(k, ω). AE = E(C N ) E(C N ). (2) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 12 / 3

Effective Hamiltonian Approach Parameters for C 2 molecule By matching energy gaps from DFT and Huckel energy levels, we can determine the hopping t 1.36 ev. By matching AE = E(2) E(21) to experimental value of 2.25 ev, we find U/t 7.1. Consistent with U values assumed in some literatures. AE (ev) 8 6 4 2-2 cage,qmc cage, ED bowl,qmc ring, QMC 1 2 3 4 5 6 7 8 9 1 U/t Parameters for C 6 molecule t 2.5 ev U/t 4 Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 13 / 3

Outline: Introduction to Fullerene molecules and solids. Effective tight-binding Hubbard model for the molecules. C 2 molecule and solid: pair-binding energies; magnetic properties; density of states, etc. C 6 molecule and solid: Single-particle excitation spectrum for solid; molecular orientations; comparison with ARPES. Some recent experimental developments. Summary. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 14 / 3

Single C 2 molecule Magnetic properties Magnetic from Huckel energy diagram; With ED and QMC: Spin triplet (magnetic) for U/t < U c /t 4.1 (3-fold orbital degeneracy); Spin singlet for U > U c (non-degenerate); Hund s rule violation; Jahn-Teller is suppressed for U > U c. Above for I h symmetry; similar for D 3d symmetry (except at U = and U c 4.19). 3 2 1 E -1-2 -3 T 2u G g G u H g T 1u A g _ I h ] ] ] ε= ε=1 ] 2.2 2.1 2.5 -.5 -.95-1 -1.5-2.23-2.24 D 3d (a) (b) (c) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 15 / 3

Single C 2 molecule Pair-binding energy b (N +1) = E(N +2) 2E(N +1)+E(N). (3) Importance of mesoscale structure in electronic mechanism of superconductivity, Chakravarty and Kivelson [Science, 1991; Phys. Rev. B, 21]; b (21)/t.2.15.1.5 (a) PQMC, I h ED, I h ED, D3D, ε=1 (b) b (21)/t b always positive absence of pair binding.. 1 2 3 4 U/t.2.15.1 t/u.5. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 16 / 3

Single C 2 molecule Jahn-Teller distortion of C 2 with I h symmetry D 3d has 4 bond lengths: a ab = 1.464Å, a bc = 1.469Å, a cc = 1.519Å, and a cc = 1.435Å, Yamamoto et al [Phys. Rev. Lett., 25]; t a /t = 1 ε(a ā)/ā, where I h (ε = ) and D 3d (ε = 1); Jahn-Teller suppressed for U > U c. b (21)/t.12.1.8.6.4 (b).5 1 ε. -.5 -.1 U=2 U=8.5 1 1.5 2 ε E (a) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 17 / 3

C 2 solid Lattice structure Solid C 2 synthesized by Wang et al [Phys. Lett. A, 21] and Iqbal et al [Eur. Phys. J. B, 23]. fcc structure; 1 additional carbon between 4 C 2 molecules. t intra-molecular hopping; t inter-molecular hopping. Cluster perturbation theory, with exact diagonalization (ED) by Sénéchal et al [Phys. Rev. Lett., 2]; with QMC by Lin et al [HPC6, p.27]. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 18 / 3

C 2 solid Metal-insulator transition Magnetic to nonmagnetic transition at U = U c ; Metal to insulator transition at U = U c, too; Appearance of gap in DOS. N(ω) N(ω) 1.2 1..8.6.4.2..3.2.1. U=2t, QMC U=5t, ED 1.39t Single C 2 Molecule FCC, t =-t (a) (b) -5-4 -3-2 -1 1 2 3 4 5 (ω µ)/t Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 19 / 3

C 2 solid Metal-insulator transition Spectral dispersions: A(k,ω) A(k,ω) U=2t, t =-t, QMC U=5t, t =-t, ED (a) (b) K Γ L W X Γ K Γ L W X -5-4 -3-2 -1 1 2 3 4 5 (ω µ)/t Γ Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 2 / 3

Outline: Introduction to Fullerene molecules and solids. Effective tight-binding Hubbard model for the molecules. C 2 molecule and solid: pair-binding energies; magnetic properties; density of states, etc. C 6 molecule and solid: Single-particle excitation spectrum for solid; molecular orientations; comparison with ARPES. Some recent experimental developments. Summary. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 21 / 3

Single C 6 molecule Pair-binding energy Perturbation calculations Chakravarty et al [Science 1992]; Ground state of C 2 6 is in spin-singlet channel at U/t > 3; b < for U/t > 3.3. QMC calculations Ground state of C 2 6 is in spin triplet channel; b > for U/t 4.5 b (61)/t.6.4.2 -.2 -.4 -.6 -.8 L=1,S=1 -.1 L=,S= PQMC -.12 1 2 3 4 5 U/t Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 22 / 3

Single C 6 molecule Density of states (DOS) (a) C 6, N=6 Neutral C 6 molecule is insulating; Three electron doped C 6 molecule is metallic. Intensity (arb. units) (b) C 6, N=63-6 -4-2 2 4 6 (E-E F )/t Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 23 / 3

C 6 monolayer Monolayer setup 2D hexagonal C 6 superlattice: Z.X. Shen s group [Science, 23; Phys. Rev. B, 25] Orientation dependent band dispersion. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 24 / 3

C 6 monolayer Intermolecular hopping matrix V = (t α Ii,Jj +t ind Ii,Jj )(c Iiσ c Jjσ +h.c.), (4) Ii,Jj σ where direct hoppings between NN molecules are given by α Ii,Jj = [V σ (d) V π (d)](ˆr Ii ˆd)(ˆR Jj ˆd)+V π (d)(ˆr Ii ˆR Jj ), (5) Satpathy et al [Phys. Rev. B, 1992], and indirect hoppings via K + ions are given by t ind Ii,Jj = γ t Ii,γ t Jj,γ ǫ C ǫ K, (6) Gunnarsson et al [Phys. Rev. B, 1998]. t Ii,γ = 1.84D 2 md 2e 3(d R min ). (7) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 25 / 3

C 6 monolayer Band dispersion matching Intermolecular hopping t and molecular orientation angle θ are variational parameters. Cluster perturbation theory. Best fit gives t =.3t, θ = 64. E-E F (ev) E-E F (ev).5 -.5 -.1 -.15 -.2 -.8 -.6 -.4 -.2.2 k // (1/Angstrom).5 -.5 -.1 -.15-64 o M Γ -.2 -.8 -.6 -.4 -.2.2 k // (1/Angstrom).9.6.3.3.25.2.15.1.5 Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 26 / 3

E-E F (ev).5 -.5 -.1 Θ= o M Γ.3.25.2.15.5.1 E-E F (ev).5 -.5 -.1 Θ=1 o M Γ.3.25.2.15.1.5 -.15 -.15 -.2 -.8 -.6 -.4 -.2.2 k // -.2 -.8 -.6 -.4 -.2.2 k // E-E F (ev).5 -.5 -.1 Θ=2 o M Γ.3.25.2.15.1.5 E-E F (ev).5 -.5 -.1 Θ=3 o M Γ.3.25.2.15.1.5 E-E F (ev).5 -.5 -.1.9.6.3 -.15 -.15 -.15 -.2 -.8 -.6 -.4 -.2.2 k // -.2 -.8 -.6 -.4 -.2.2 k // -.2 -.8 -.6 -.4 -.2.2 k // (1/Angstrom) E-E F (ev).5 -.5 -.1 Θ=4 o M Γ.3.25.2.15.1.5 E-E F (ev).5 -.5 -.1 Θ=5 o M Γ.3.25.2.15.1.5 E-E F (ev).5 -.5 -.1-64 o M Γ.3.25.2.15.1.5 -.15 -.15 -.15 -.2 -.8 -.6 -.4 -.2.2 k // -.2 -.8 -.6 -.4 -.2.2 k // -.2 -.8 -.6 -.4 -.2.2 k // (1/Angstrom) E-E F (ev).5 -.5 -.1 Θ=6 o M Γ.3.25.2.15.1.5 E-E F (ev).5 -.5 -.1 Θ=7 o M Γ.3.25.2.15.1.5 -.15 -.15 -.2 -.8 -.6 -.4 -.2.2 -.2 -.8 -.6 -.4 -.2.2 k // k // Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 27 / 3

C 6 monolayer Monolayer DOS Evolution of DOS with U and electron doping. Comparison with experimental PES. (a) C 6 monolayer, U= (a) C 6 monolayer exp QMCPT Intensity (arb. units) (b) C 6 monolayer, U=4t (c) K 3 C 6 monolayer, U=4t Intensity (arb. units) (b) K 3 C 6 monolayer exp QMCPT -6-5 -4-3 -2-1 1 2 3 4 5 6 (E-E F )/t -1-8 -6-4 -2 E-E F (ev) Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 28 / 3

Recent developments in experiments Future projects K 4 C 6 monolayer, Crommie group [Science, 25]; K x C 6 monolayers 3 x 5, Crommie group [Phys. Rev. Lett., 27]; Why is K 4 C 6 insulating? Jahn-Teller? Role of orientational ordering? Cs 3 C 6 superconductor, Rosseinsky group [Science, 29] T c = 38K; disorder-free parent state: AF insulator; pressure-inudced SC unconventional superconductor Single molecule transistors: Winkelmann et al [Nature Physics 29], Yu et al [Nano Lett. 24], etc. Can we calculate transport property? Carbon is light. Intramolecular vibration frequency up to.2 ev; E F =.3 ev. Can we include Carbon dynamics in QMC? Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 29 / 3

Summary Effective tight-binding Hubbard model can capture most of the physics of Fullerene molecules; U/t increases with molecular curvature: C 2 is the most correlated molecule; C 2 molecule/solid undergoes magnetic metal to nonmagnetic insulator transition at U c /t 4.1; Neutral C 2 is an insulator; Jahn-Teller distortion is suppressed in C 2 molecule since U/t 7.1; Neutral C 6 is an insulator; K 3 C 6 a metal; Not able to find favorable pair binding from b calculations. Able to compare with ARPES for molecular orientation dependent band dispersion. Fei Lin (Virginia Tech) Correlations in Fullerene SESAPS 211, Roanoke, VA 3 / 3

2024 © sciencedocbox.com Privacy Policy | Terms of Service | Feedback