量子力学英文版全套教学课件.pptx

Quantum Mechanics量子力学全套课件;§1.1 Wave-Particle Duality;3. Compton effect ? The momentum of photons: Wave-particle duality 1. de Broglie’s hypothesis : de Broglie wave 2. Heisenberg’s uncertainty principle ;§1.2 Basic Postulates of Quantum Mechanics; Hermitian operator given by the following rules: (1) The operator corresponding to the Cartesian position x is x ?— similarly for the coordinates y and z. (2) The operator corresponding to , the x component of linear momentum, is ----similarly for the y and z components. (3) To obtain the operator corresponding to any other observable, first write down the classical expression for the observable in terms of x,y,z, ,and then replace each of these quantities by its corresponding operator according to rules (1) and (2) . ;3. The only possible result which can be obtained when a measurement is made of an observable whose operator is ? is an eigenvalue of ?. 4. Let A be an observable whose operator ? has a set of eigenfunctions with corresponding eigenvalues . If a large number of measurements of A are made on a system in the state ?, then the expectation value （期望值）of A for the state ? (I.e. the arithmetic mean （算术平均）of the eigenvalues obtained) is given by , where d? is an element of volume, and the integral is taken over all space. ;5. The time variation of the state function of a system is given by , where ? is operator formed from the classical Hamiltonian of the system. ? Basic deduction from the postulates: Probability of result of measurement ? Suppose the eigenvalues of ? in postulates 4 and 5 are discrete, and that the state function ? and all the eigenfunctions of ? are normalized.To find the probability that the result of a measurement of the observable A is a particular