Physics 240B Problem Set #2 (20)
1.
M. L. Cohen
Spring 2008 Due: 02/26/08
Find and solve the quantum equations of motion for a free electron in a magnetic r field using the gauge A = (-1/2Hy, 1/2Hx, O). Show that for an electron in a magnetic fiel
Solar energy
4.3 x 1020 J : sunlight energy striking the Earth in 1 hour (120 PW). 4.1 x 1020 J : global energy consumption in 1 year (13 TW).
In 2050 it is projected that we will be at 30 TW.
Current solar electricity utilization:
10-6 o
Physics 240B, Spring 2008 Homework 3 Solutions
Jesse Noffsinger April 7, 2008
Solutions are in general not the original work of the author.
Problem 1)
The "Ultimate efficiency" of a single-gap solar cell.
a)
The total power is the intensity times
Physics 240B Problem Set #3 (20)
1.
M. L. Cohen
Spring 2008 Due: 03/18/08
"Ultimate efficiency" of a single-gap solar cell. The goal of this problem is to derive an upper bound on the power conversion efficiency-defined here as the ratio of output
PHYSICS 240B
Time & Place: Office Hours: Reader:
M. L. COHEN
Tu & Th, 11:00 AM 12:30 PM, 385 Le Conte Tu & Th, before class or by appointment, 539 Birge Jesse Noffsinger 542 Birge
SPRING 2008
Office Hour: Mon. 1:302:30 pm
Discussion Section: W 2
Physics 240B Problem Set #1 (20) 1.
M. L. Cohen
Spring2008 Due: 02/12/08
As a review, treat a metal as a free electron gas and calculate: (a) the density of states as a function of wave vector and as a function of energy, (b) the density of states
Physics 240B, Spring 2008 Homework 1 Solutions
Jesse Noffsinger February 14, 2008
Solutions are in general not the original work of the author.
Problem 1)
Chapter 6 of Kittel is very helpful for this problem. Portions not worked out explicitly here
Physics 240B, Spring 2008 Homework 2 Solutions
Jesse Noffsinger April 6, 2008
Solutions are in general not the original work of the author.
Problem 1)
The Hamiltonian is given by H= 1 2m px + eH y 2c
2
+ py +
eH x 2c
2
+ p2 z
(1)
In the Heise
Physics 240B, Spring 2008 Homework 4 Solutions
Jesse Noffsinger May 1, 2008
Solutions are in general not the original work of the author.
Problem 1)
a)
Calculate the mean square radius of a Cooper pair: The Cooper pair wavefunction is given by: (r)
Physics 240B Problem Set #5 (20)
M. L. Cohen
Spring 2008 Due: 05/01/08
1. For a weakly coupled BCS superconductor such as Al at T = 0, find the ratio of the radius rp characterizing the spherical volume per pair and the coherence length. Express y
Physics 240B Problem Set #4 (20) 1. For the Cooper pair problem:
M. L. Cohen
Spring 2008 Due: 04/15/08
(a) Calculate the mean square radius of a Cooper pair. (b) How does the energy of the bound pair vary with center of mass momentum? What does th