ARPES (Angle Resolved PhotoEmission Spectroscopy) Michael Browne 11/19/2007.

Slides:

Advertisements

Similar presentations

X-ray Photoelectron Spectroscopy

Advertisements

Spectroscopy Photoelectron spectroscopy X-ray absorption spectroscopy

Wave-Particle Duality

Gamma-Ray Spectra _ + The photomultiplier records the (UV) light emitted during electronic recombination in the scintillator. Therefore, the spectrum collected.

Spectroscopy Photoelectron spectroscopy X-ray absorption spectroscopy

1 My Chapter 27 Lecture. 2 Chapter 27: Early Quantum Physics and the Photon Blackbody Radiation The Photoelectric Effect Compton Scattering Early Models.

Knight - Chapter 28 (Grasshopper Book) Quantum Physics.

Cutnell/Johnson Physics 7th edition

Which of the following statements on the photoelectric

Blackbody Radiation & Planck’s Hypothesis

1 Light as a Particle The photoelectric effect. In 1888, Heinrich Hertz discovered that electrons could be ejected from a sample by shining light on it.

Geant4 Low Energy Polarized Compton Processes Gerardo Depaola * Francesco Longo + Francesco Longo + * National University of Córdoba (Argentina) + University.

Ultraviolet Photoelectron Spectroscopy (UPS)

Blackbody Radiation & Planck’s Hypothesis

Chapter 27 Quantum Physics.  Understand the relationship between wavelength and intensity for blackbody radiation  Understand how Planck’s Hypothesis.

Amal Al-Wahish Course: Solid state 672 Prof. Dagotto Department of Physics, UTK.

Many sources (hot, glowing, solid, liquid or high pressure gas) show a continuous spectra across wavebands. Emission spectra Elements in hot gases or.

Lecture 18. Chemical: XPS.

1 Light as a Particle In 1888, Heinrich Hertz discovered that electrons could be ejected from a sample by shining light on it. This is known as the photoelectric.

Phys 102 – Lecture 25 The quantum mechanical model of light.

Bohr model 1. Electrons revolve around nucleus in circular paths, like planets around the sun. He called these paths orbits. 2. Each orbit has a specific.

Classical vs Quantum Mechanics Rutherford’s model of the atom: electrons orbiting around a dense, massive positive nucleus Expected to be able to use classical.

What’s wrong with this picture? The attractive Coulomb force between the positive nucleus and the orbiting electron could provide the attractive force.

Adventures and Opportunities with Ted Madey using Synchrotron Radiation Photoemission John E. (Jack) Rowe, Physics Department, North Carolina State University.

G. Energy of a photon You should be able to: describe the particulate nature (photon model) of electromagnetic radiation state that a photon is a quantum.

the photoelectric effect. line spectra emitted by hydrogen gas

Young/Freeman University Physics 11e. Ch 38 Photons, Electrons, and Atoms © 2005 Pearson Education.

Photoemission Spectroscopy Dr. Xiaoyu Cui May Surface Canada workshop.

1 PHYS 3313 – Section 001 Lecture #8 Monday, Sept. 23, 2013 Dr. Amir Farbin Discovery of Electron Determination of Electron Charge Line Spectra Blackbody.

1 My Chapter 28 Lecture. 2 Chapter 28: Quantum Physics Wave-Particle Duality Matter Waves The Electron Microscope The Heisenberg Uncertainty Principle.

Chapter 8: Electrons in Atoms

1 PHYS 3313 – Section 001 Lecture #10 Monday, Feb. 17, 2014 Dr. Jaehoon Yu Photoelectric Effect Compton Effect Pair production/Pair annihilation Monday,

EEE 3394 Electronic Materials Chris Ferekides Fall 2014 Week 6.

Thompson’s experiment (discovery of electron) + - V + - Physics at the end of XIX Century and Major Discoveries of XX Century.

In an experiment to demonstrate the photoelectric effect, you shine a beam of monochromatic blue light on a metal plate. As a result, electrons are emitted.

Baby-Quiz 1.Why are diffraction effects of your eyes more important during the day than at night? 2.Will the converging lens focus blue light or red light.

Resolution Limits for Single-Slits and Circular Apertures  Single source  Two sources.

Quantum Physics. What makes one atom different from another? atom The amazing colors produced in fireworks are a result of the different types of atoms.

1.Stable radiation source 2.Wavelength selector 3.Transparent sample holder: cells/curvettes made of suitable material (Table 7- 2) 4.Radiation detector.

Weird experiments Schrödinger equation.

Warm-Up Lithium has an atomic weight of g/mol. When g of lithium is heated, it emits an energy measured at 262,500 joules. What is the energy.

Goal: To understand how light acts like a particle Objectives: 1)To learn about Quantization 2)To understand Blackbody radiation 3)To learn more about.

THE PHOTOELECTRIC EFFECT Objective: Demonstrate the particle nature of light by discussing photoelectric effect. Albert EinsteinTM HUJ,

THE PHOTOELECTRIC EFFECT

THE PHOTOELECTRIC EFFECT. When red light is incident on a clean metal surface: no electrons are released, however long light is shone onto it, however.

1.1 What’s electromagnetic radiation

Spectral Response of GaAs(Cs, NF 3 ) Photocathodes Teresa Esposito Mentors: I. Bazarov, L. Cultrera, S. Karkare August 10, 2012.

Unit 12: Part 2 Quantum Physics. Overview Quantization: Planck’s Hypothesis Quanta of Light: Photons and the Photoelectric Effect Quantum “Particles”:

Electrons in Solids Simplest Model: Free Electron Gas Quantum Numbers E,k Fermi “Surfaces” Beyond Free Electrons: Bloch’s Wave Function E(k) Band Dispersion.

QUANTUM AND NUCLEAR PHYSICS. Wave Particle Duality In some situations light exhibits properties that are wave-like or particle like. Light does not show.

1© Manhattan Press (H.K.) Ltd Photoelectric effect Investigation of photoelectric effect Explanation of photoelectric effect by quantum theory Types.

Pre-Quantum Theory. Maxwell A change in a electric field produced a magnetic field A change in a magnetic field produced an electric field.

Raman spectroscopy.

3.1 Discovery of the X-Ray and the Electron 3.2Determination of Electron Charge 3.3Line Spectra 3.4Quantization 3.5Blackbody Radiation 3.6Photoelectric.

Angle-resolved photoemission spectroscopy (ARPES)

The Compton Effect Topic 14.3.

The Wacky World of Quantum Physics

Matter Waves and Uncertainty Principle

Photons: Light Waves Behaving as Particles

Search for Novel Quantum Phases in

Photoelectric Effect Topic 14.2.

Finish up the photoelectric effect

What is the nature of Light ? Part II.

What is Light? Light is an electromagnetic wave.

Measuring the quantum numbers E,k of electrons in a solid

Interaction of Electromagnetic Radiation with Matter

Chapter 29 Photoelectric Effect

What is Light? Light is an electromagnetic wave.

Photoelectric Effect And Quantum Mechanics.

Surface analysis techniques part I

Presentation transcript:

ARPES (Angle Resolved PhotoEmission Spectroscopy) Michael Browne 11/19/2007

What is ARPES? An atomically flat sample is illuminated by a beam of monochromatic light. Due to the photoelectric effect, the sample emits electrons. The kinetic energy and direction of these electrons are measured by the apparatus. This data reflects the structure of the Fermi surface within the material.

What is ARPES?

The ARPES Apparatus at SSRL Photon energies of eV Angular resolution of Energy resolution of 2-10 MeV

The Photoelectric Effect Explained by Einstein (1905): More generally, where is the binding energy of the electron.

Photoemission Spectra The work function is known/measurable. The photon energy is known. We can calculate the energy of the electron in the solid!

Theoretical Basis of ARPES Point #1: The flat surface of the sample has translational symmetry. Therefore, as electrons escape from the solid, linear momentum is conserved parallel to the surface.

Theoretical Basis of ARPES Point #2: (See Table 2.1) The photon momentum is small and can be neglected!

Theoretical Basis of ARPES Conclusion: ARPES is directly measuring the components of electron momentum that are parallel to the surface! How many electrons of a given momentum will ARPES measure?

Theoretical Basis of ARPES Theoretically, the measured intensity can be described as: where depends on the photon. is the Fermi-Dirac distribution. is the one-particle spectral function.

What is ARPES used for? ARPES is an almost ideal tool for imaging the Fermi surface of 1-D and 2-D solids. Since many of the high temperature superconductors are essentially 2-D materials, much of the work in this field is done using ARPES.

Momentum and Binding Energy

Direct k Space Imaging

Fermi Surface Images

Band Structure Images

: Theoretical Calculation Validation of Predictions : ARPES Measurement

Disadvantages of ARPES Must be done in an ultrahigh vacuum (otherwise electrons would collide) so cannot measure pressure effects. Cannot measure magnetic effects (a magnetic field would deflect electrons). Only measures surface effects in the top 10 Å or so.

Laser ARPES: lower energy means sharper pictures (image of in “nodal” direction) Further Advances

Credits Slide 1,13: Slide 3-5,12: alks/ARPES_Intro.pdf alks/ARPES_Intro.pdf Slide 14, 15: Slide 16: ssrl.slac.stanford.edu/research/highlights_archive/high-tc.htmlhttp://www- ssrl.slac.stanford.edu/research/highlights_archive/high-tc.html Slide 18: