LectureNotesforSolidStatePhysics (3rdYearCourse6 ...

1 Lecture Notes for Solid State Physics(3rd Year Course 6)Hilary Term 2012c Professor Steven H. SimonOxford UniversityJanuary 9, 2012iShort Preface to My Second Year Lecturing This CourseLast year was my first year teaching this course. In fact, it was myfirst experience teachingany undergraduate course. I admit that I learned quite a bit from the experience. The good newsis that the course was viewed mostly as a success, even by the tough measure of student reviews. Iparticularly would like to thank that student who wrote on his or her review that I deserve a raise and I would like to encourage my department chair to post this review on his wall and refer toit luck, the second iteration of the course will be even better than the first. Havinglearned so much from teaching the course last year, I hope to improve it even further for this of the most important things I learned was how much students appreciate a clear, complete,and error-free set of notes.

2 As such, I am spending quite a bit of time reworking these notes tomake them as perfect as my plea from last year, if you can think of ways that thesenotes (or this course)could be further improved (correction of errors or whatnot) please let me know. The next generationof students will certainly appreciate it and that will improve your Karma.,Oxford, United KingdomJanuary, I was an undergraduate, I thought solid state physics (a sub-genre of condensed matterphysics) was perhaps the worst subject that any undergraduate could be forced to learn boringand tedious, squalid state as it was commonly called1. How much would I really learn about theuniverse by studying the properties of crystals? I managed to avoid taking this course opinion at the time was not a reflection of the subject matter, but rather was a reflection ofhow solid state physics was my opinion as an undergraduate, it is a bit ironic that I have become a condensedmatter physicist.

3 But once I was introduced to the subject properly, I found that condensed matterwas my favorite subject in all of physics full of variety, excitement, and deep ideas. Many manyphysicists have come to this same conclusion. In fact, condensed matter physics is by far the largestsingle subfield of physics (the annual meeting of condensed matterphysicists in the United Statesattracts over 6000 physicists each year!). Sadly a first introduction to the topic can barely scratchthe surface of what constitutes the broad field of condensed year when I was told that a new course was being prepared to teach condensed matterphysics to third year Oxford undergraduates, I jumped at the opportunity to teach it. I felt thatitmustbe possible to teach a condensed matter physics course that is just as interesting andexciting as any other course that an undergraduate will ever take. It must be possible to conveythe excitement of real condensed matter physics to the undergraduate audience.

4 I hope I willsucceed in this task. You can judge for topics I was asked to cover (being given little leeway in choosing the syllabus) are notatypical for a solid state physics course. In fact, the new condensed matter syllabus is extremelysimilar to the old Oxford B2 syllabus the main changes being the removal of photonics and devicephysics. A few other small topics, such as superconductivity and point-group symmetries, are alsononexaminable now, or are removed altogether . A few other topics(thermal expansion, chemicalbonding) are now added by mandate of the any rate, the changes to the old B2 syllabus are generally minor, so I recommend thatOxford students use the old B2 exams as a starting point for figuring out what it is they need tostudy as the exams approach. In fact, I have used precisely these old exams to figure out what Ineed to teach. Being that the same group of people will be setting the exams this year as set themlast year, this seems like a good idea.

5 As with most exams at Oxford, one starts to see patternsin terms of what type of questions are asked year after year. Thelecture notes contained here aredesigned to cover exactly this crucial material. I realize that thesenotes are a lot of material, andfor this I apologize. However, this is theminimumset of notes that covers all of the topics thathave shown up on old B2 exams. The actual lectures for this coursewill try to cover everythingin these notes, but a few of the less crucial pieces will necessarily beglossed over in the interest of these topics are covered well in standard solid state physics references that onemight find online, or in other books. The reason I am giving these lectures (and not just tellingstudents to go read a standard book) is because condensed matter/solid-state is an enormoussubject worth many years of lectures and one needs a guide to decide what subset of topics1 This jibe against solid state physics can be traced back to the Nobel Laureate Murray Gell-Mann, discovererof the quark, who famously believed that there was nothing interesting in any endeavor but particle he now studies complexity a field that mostlyarose from condensed can discuss elsewhere whether or not we should pay attention to such mandates in general although theseparticular mandates do not seem so most important (at least in the eyes of the examination committee).

6 I believe that the lecturescontained here give depth in some topics, and gloss over other topics, so as to reflect the particulartopics that are deemed important at Oxford. These topics may differ a great deal from what isdeemed important elsewhere. In particular, Oxford is extremely heavy on scattering theory (x-rayand neutron diffraction) compared with most solid state courses orbooks that I have seen. Buton the other hand, Oxford does not appear to believe in group representations (which resulted inmy elimination of point group symmetries from the syllabus).I cannot emphasize enough that there are many many extremely good books on solid-stateand condensed matter physics already in existence. There are alsomany good resources online (in-cluding the rather infamous Britney Spears guide to semiconductor physics which is tongue-in-cheek about Britney Spears3, but actually is a very good reference about semiconductors).

7 Iwill list here some of the books that I think are excellent, and throughout these lecture notes, Iwill try to point you to references that I think are helpful. States of Matter, by David L. Goodstein, DoverChapter 3 of this book is a very brief but well written and easy to read description of muchof what we will need to cover (but not all, certainly). The book is also published by Doverwhich means it is super-cheap in paperback. Warning: It uses cgs units rather than SI units,which is a bit annoying. Solid State Physics, 2nd edby J. R. Hook and H. E. Hall, WileyThis is frequently the book that students like the most. It is a first introduction to thesubject and is much more introductory than Ashcroft and Mermin. The Solid State, by H M Rosenberg, OUPThis slightly more advanced book was written a few decades ago to cover what was the solidstate course at Oxford at that time. Some parts of the course have since changed, but otherparts are well covered in this book.

8 Solid-State Physics, 4ed, by H. Ibach and H. Luth, Springer-VerlagAnother very popular book on the subject, with quite a bit of information in it. Moreadvanced than Hook and Hall Solid State Physics, by N. W. Ashcroft and D. N. Mermin, Holt-SandersThis is the standard complete introduction to solid state physics. Ithas many many chapterson topics we won t be studying, and goes into great depth on almost everything. It may bea bit overwhelming to try to use this as a reference because of information-overload, butit has good explanations of almost everything. On the whole, this is myfavorite : Also uses cgs units. Introduction to Solid State Physics, 8ed, by Charles Kittel4, WileyThis is a classic text. It gets mixed reviews by some as being unclear onmany matters. Itis somewhat more complete than Hooke and Hall, less so than Ashcroft and Mermin. Itsselection of topics and organization may seem a bit strange in the modern era.

9 The basics of Crystallography and Diffraction, 3ed, by C Hammond, OUPThis book has historically been part of the syllabus, particularly for the scattering theorypart of the course. I don t like it guide was written when Ms. Spears was just a popular young performer and not the complete train wreckthat she appears to be happens to be my dissertation-supervisor s dissertation-supervisor s dissertation-supervisor s dissertation-supervisor, for whatever that is Structure and Dynamics, by Dove, Oxford University PressThis is a more advanced book that covers scattering in particular. It is used in the CondensedMatter option 4-th year course. Magnetism in Condensed Matter, by Stephen Blundell, OUPWell written advanced material on the magnetism part of the course. It is used in theCondensed Matter option 4-th year course. Band Theory and Electronic Properties of Solids, by John Singleton, OUPMore advanced material on electrons in solids.

10 Also used in the Condensed Matter option4-th year course. Solid State Physics, by G. Burns, AcademicAnother more advanced book. Some of its descriptions are short but very will remind my reader that these notes are a first draft. I apologize that they do not coverthe material uniformly. In some places I have given more detail thanin others depending mainlyon my enthusiasm-level at the particular time of writing. I hope to goback and improve the qualityas much as possible. Updated drafts will hopefully be this pile of notes will end up as a book, perhaps they will is not mypoint. My point is to write something that will be helpful for this course. If you can think of waysthat these notes could be improved (correction of errors or whatnot) please let me know. The nextgeneration of students will certainly appreciate it and that will improve your Karma.,Oxford, United KingdomJanuary, to say, I pilfered a fair fraction of the content of this course from parts of otherbooks (mostly mentioned above).