Physics 602: Graduate Solid State Physics II

Adventures in Quantum Materials:
A Selected Survey of Great Papers from Last Year
and Last Century (and maybe even Last Week!)

Spring 2021

     10:00 a.m. - 12:00  p.m.

Course Instructor:  Prof.  Premi Chandra                                       

Overview:   Societal developments of human history are deeply connected with the discovery of new materials with novel properties.   For example our current information technologies are made possible by the development of silicon transistors.  However current limitations on computing call for new materials manifesting entangled quantum physics; here entanglement denotes the absence of any local quantities describing the individual quantum state.  With tremendous advances in materials synthesis and the emergence of quantum information,  there is great opportunity for the cross-fertilization of ideas towards the identification and characterization of new quantum materials, both for their fundamental properties and towards practical applications.

In this course we will explore outstanding questions posed by quantum materials through discussion of key experimental and theoretical results from the 20th century to breakthroughs of today.  The course will meet once a week, Thursday 10:00 am - 12:00 pm, and will take a reading/seminar format; I will provide background information/context as needed.  Each session we will discuss a few (2-4) papers on a specific topic with the aim to link to research areas of ongoing interest.  Possible themes to be explored include

a) the observation of antiferromagnetism and the subsequent emergence of quantum spin liquids and other novel spin states

b) BCS theory of superconductivity, its experimental confirmation and more recently materials that demand further theoretical understanding

c)  the observation of the fractional Quantum Hall effect, the identification of topological insulators and the challenges
and promises of twisted bilayer materials

d)  the opportunities presented by machine learning in strongly correlated quantum materials

e)  quantum circuitry:  where are we now towards realizing concepts of quantum information?

f) fractional charge and composite realizable are these concepts (and do they have applications?)?

(Syllabus to be developed "organically" after first organizational meeting depending on class interests)

  Tentative Syllabus


   Jan. 21

                                                Introduction/Overview/Organizational Meeting

                                                          Introduction/"Taster" Journal Club
                                               Signatures of Wigner Crystals in TMD Heterostructures
                                                              Wigner Crystal IPad Notes


   Jan. 28

                                                              Classical Magnetic Frustration
                                                  (Spin Systems as "Economy" Strongly Correlated Systems)
                                                                      Lecture Slides
                                                                    Lecture IPad Notes

                                                                 Geometric Frustration
                                                                           Spin Ice

                                                              Magnetic Monopoles in Spin Ice


   Feb. 4

                                                                   More Frustrated Spin Systems

                                                                        Lecture Slides
                                                                      Lecture IPad Notes

                                                                Order by Disorder and Topology

                                                              Spin Ice, Fractionalization and Topological Order

   Feb. 11

Spin Liquids

Lecture Slides
Lecture IPad Notes
A Field Guide to Spin Liquids
Quantum Spin Liquids

   Feb. 18

Kitaev Spin Liquids I

Lecture Slides
Lecture IPad Notes

G. Ramirez "Lithium Ion Batteries"
  C. Trout, "Spin Waves & Neutron Scattering"
K. Lucht, "The Aharonov-Bohm Effect"

Physics of the Kitaev Model:  Fractionalization, Dynamic Correlations
and Material Connections

Kitaev Quantum Spin Liquids - Concept and Materialization


  Feb. 25

Kitaev Spin Liquids II

Lecture Slides
Lecture IPad Notes

Y.-T. Chan "Infinite-Layered Nickelates"
M. Terilli "Thin-Film Pyrochlore Irridates"

Kitaev Materials

  March 4

Experimental Detection of Majorana Fermions?

Lecture Slides
Lecture IPad Notes

S. Rao "Twisted Bilayer Graphene"
Soliton Signature in the Phonon Spectrum of
Twisted Bilayer Graphene

Majorana Returns

Hunting Majorana Fermions in Kitaev Magnets

  March 11

                                             Experimental Detection of Majorana Fermions?  (cont.)

                                                                        Lecture Slides                              

                                                        The Heat is on for Majorana Fermions

                Majorana Quantization and Half-Integer Thermal QuantumHall  Effect in a Kitaev Spin Liquid

  March 19

                                                                       Spring Break

  March 25 
                                Evidence of Majorana Particles Dies with Retraction (3/18/21)

                                                                   Lecture Slides
                                                                Lecture IPad Notes

         The 2018 Excitement:
                      Quantized, Finally (News and Views Commentary)
                      Quantized Majorana Conductance
                      Retraction Note:  Quantized Majorana Conductance (3/21) 
          The 2021 Analysis:
                      Major(ana) Backpedaling:  Microsoft-Backed Quantum Computer Research Retracted
                                      (Commentary in IEEE Spectrum 3/17/21)
                      Non-Majorana States Yield Nearly Quantized Conductance in Proximatized Nanowires

  April 1

Two-Dimensional Vortex Lattice Melting

Lecture Slides
Lecture IPad Notes

Introduction to Superconductivity (C. Yu)

Melting of Two-Dimensional Solids

Melting of the Vortex Lattice through Intermediate Hexatic
Fluid in an \alpha-MoGe Thin Film

(Journal Paper Presentation)

  April 8

Class "Meets" on Monday April 12th (10 - 12)
(Weekly Open Discussion to be Rescheduled)

Upping the Anti
The Multiple Directions of Antiferromagnetic Spintronics

Coherent Terahertz Control
Terahertz Control of Antiferromagnetic Spin Waves 
Journal Paper Presentation Slides (C. Trout)

Nanoscale Mechanics of Antiferromagnetic Domain Walls
Journal Paper Presentation Slides (Y.-T. Chan)

  April 15

Class "Meets" on Monday April 19th (10 - 12)
(Weekly Open Discussion to be Rescheduled)

Introduction to the Toric Code (P. Herringer)
The Toric Code (B. Terhal)
Realizing Topologically Ordered States on a Quantum Processor
(Google Collaboration, April 2, 2021 preprint!)

Fault-Tolerant Toric Code by Anyons
Journal Paper Presentation (K. Lucht)


Graphene Bilayers with a Twist (E. Andrei and A.H. MacDonald)

Density Waves in Twisted Double Bilayer Graphene
Journal Paper Presentation (S. Rao)

  April 22

Promising All-Solid-State Batteries for Future Electric Vehicles

Efficient and Stable Bi and Sb Anodes in Solid State Lithium Batteries
Journal Paper Presentation (G. Ramirez)

  April 29

Weyl Semimetals, Fermi Arcs and Chiral Anomalies

Signature of a Chiral Anomaly in a Weyl Semimetal  
Journal Paper Presentation (M. Terilli)

On the Search for the Chiral Anomaly in Weyl Semimetals:
The Negative Magnetoresistance