What is Solid State Physics Reminder of the

What is “Solid State” Physics? ?

Reminder of the Course Objective • To expose students to the rich, broad, varied field of SOLID STATE PHYSICS • This ISN'T a semiconductor physics course!! • A semiconductor course is Physics 5335, Semiconductor Physics It is offered in the fall of even numbered years.

• Solid State Physics is about many different kinds of solids. • Semiconductors are a special category. • We'll discuss the microscopic physics of mostly, CRYSTALLINE solids, including metals, insulators, & semiconductors. • This course is complementary to, but it ISN'T a replacement for Physics 5335!!

Decreasing Size The Structure of Physics Increasing Speed Large Size >> Atomic Size Small Size < ~ Atomic Size Low Speed High Speed v << c Classical Mechanics v < ~ c Special Relativity (Newton, Hamilton, Lagrange) (Einstein) Quantum Mechanics Relativistic Quantum (Schrodinger, Heisenberg) Mechanics (Dirac) Atomic Physics Quantum Field Quantum Theory Electrodynamics Molecular (Chemical) Physics Solid State Physics Nuclear & Particle Physics Quantum Chromodynamics (Gluons, Quarks, Feynman, Schwinger, Gell-Mann (Photon) Leptons, Strong (Weak Nuclear Force)

Decreasing Size The Structure of Physics Increasing Speed Large Size >> Atomic Size Small Size < ~ Atomic Size In this course, our focus will be here! Low Speed High Speed v << c Classical Mechanics v < ~ c Special Relativity (Newton, Hamilton, Lagrange) (Einstein) Quantum Mechanics Relativistic Quantum (Schrodinger, Heisenberg) Mechanics (Dirac) Atomic Physics Quantum Field Quantum Theory Electrodynamics Molecular (Chemical) Physics Solid State Physics Nuclear & Particle Physics Quantum Chromodynamics (Gluons, Quarks, Feynman, Schwinger, Gell-Mann (Photon) Leptons, Strong (Weak Nuclear Force)

What is “Solid State Physics”? • “Solid State Physics” can be ~ defined as the study of the microscopic properties of the dense assembly of electrons formed by placing atoms very close together in a solid. • A very large, very broad physics sub-field. • In some sense, Solid State Physics is “the opposite” of Particle Physics focuses on properties of INDIVIDUAL particles. • Particle physicists break composite objects up into constituent building blocks.

What is “Solid State Physics”? • Solid State Physics deals with the microscopic properties of large COLLECTIONS of particles. • Solid State physicists are interested in what fundamentally NEW PROPERTIES emerge when these building blocks are grouped together in various ways.

Motivations for the Study of Solid State Physics • There are Technological & Basic Physics motivations to study Solid State Physics. Technological Motivations • A very important motivation is that the microscopic properties Solid State Physics deals with are responsible for the majority of modern technology.

Motivations for the Study of Solid State Physics Technological Motivations • A very important motivation is that the microscopic properties Solid State Physics deals with are responsible for the majority of modern technology. • These properties determine the mechanical strength of materials, how they interact with light, how they conduct electricity, etc. • So, Solid State Physics is important for technology, because it gives guidance on the design of circuits needed for modern electronic devices. This field gave us the transistor & the semiconductor chip!

Technological Motivations This field gave us the transistor & the semiconductor chip! • So, Solid State Physics is traditionally linked to materials science, chemistry & engineering. • Recently, it has developed overlaps with biology, biochemistry, biotechnology & medicine. • So, many current research questions in Solid State Physics are still at the frontiers of applied science & next-generation technologies.

Basic Physics Motivations • A very important motivation to study Solid State Physics is that the fundamental physics needed to understand the microscopic properties of solids is very interesting. • To understand these properties, the ideas & methods of quantum mechanics must be used. The physics of solids is VERY deeply quantum mechanical.

Basic Physics Motivations • The physics of solids is VERY deeply quantum mechanical. • Solid State Physics has sometimes been called the best “laboratory” for studying subtle quantum mechanical effects. • This course may be a first chance for students to see quantum mechanical ideas & methods applied to cases where their technological consequences are so important.

• 2 examples (of MANY!) in which Solid State Physics discoveries have revealed very interesting, fundamental physics are the observations & explanations of 1. Superconductivity 2. The Fractional Quantum Hall Effect

1. Superconductivity 2. The Fractional Quantum Hall Effect • Both have exotic quantum mechanical explanations. • A very strong indicator that Solid State Physics has led (& continues to lead!) to the understanding of many very interesting basic physics phenomena is the fact that: More than 40% of Physics Nobel Prizes in the past 40 years & 50% of those in the past 10 years have been for work in Solid State Physics!!!!

The Solid State Physics Research Area • Many of you are likely taking this course because it is related to your research area. If so, you've chosen a very good, interesting field! LARGE quantities of new physics is discovered in this area all of the time. • For example, the American Physical Society's (APS) Division of Condensed Matter Physics or DCMP ("Condensed Matter" is ~ the same as “Solid State”) is, BY FAR, the largest APS division! ~(1/3) of the ~ 60, 000 APS members belong to the DCMP.

Solid State Physics Research Area • Another APS division is the Division of Materials Physics or DMP (“Materials Physics” is ~ the same as “Applied Solid State”), which started ~25 years ago. The DMP is rapidly growing & may eventually become similar in size to the DCMP. (Many people belong to both!). • BY FAR, the largest annual APS meeting is the joint DCMP & DMP meeting. It is held each March (it's called the “March Meeting”!). 2019 March Meeting (Boston, MA): ~10, 000 + people & ~7, 500+ papers!

The APS No matter what your research area is Every Physics Graduate Student, + every undergrad who wants to go to graduate school! should join the APS!! • The first year's membership is FREE to students & the following student years are highly discounted!

The MRS Graduate students working in Solid State, Condensed Matter, or Materials Physics should also consider joining the Materials Research Society (MRS)! • The MRS is another large professional organization, but it has a very interdisciplinary membership. • This reflects the fact that people with many different backgrounds are doing various kinds of materials research. For example, it has members with backgrounds in Physics, in Chemistry, & in various types of Engineering.

Relationship of Solid State Physics to Other Physics Sub-Areas: • Solid State Physics Research often benefits from interaction with researchers from other sub-areas of physics & from engineering. • So, often, it is truly interdisciplinary in nature. • This aspect of it is illustrated abstractly in the figure