Title
A level set method for the semiclassical limit of the Schrödinger equation with discontinuous potentials
Abstract
We propose a level set method for the semiclassical limit of the Schrodinger equation with discontinuous potentials. The discontinuities in the potential corresponds to potential barriers, at which incoming waves can be partially transmitted and reflected. Previously such a problem was handled by Jin and Wen using the Liouville equation - which arises as the semiclassical limit of the Schrodinger equation - with an interface condition to account for partial transmissions and reflections (S. Jin, X. Wen, SIAM J. Num. Anal. 44 (2006) 1801-1828). However, the initial data are Dirac-delta functions which are difficult to approximate numerically with a high accuracy. In this paper, we extend the level set method introduced in (S. Jin, H. Liu, S. Osher, R. Tsai, J. Comp. Phys. 210 (2005) 497-518) for this problem. Instead of directly discretizing the Delta functions, our proposed method decomposes the initial data into finite sums of smooth functions that remain smooth in finite time along the phase flow, and hence can be solved much more easily using conventional high order discretization schemes. Two ideas are introduced here: (1) The solutions of the problems involving partial transmissions and partial reflections are decomposed into a finite sum of solutions solving problems involving only complete transmissions and those involving only complete reflections. For problems involving only complete transmission or complete reflection, the method of JLOT applies and is used in our simulations; (2) A reinitialization technique is introduced so that waves coming from multiple transmissions and reflections can be combined seamlessly as new initial value problems. This is implemented by rewriting the sum of several delta functions as one delta function with a suitable weight, which can be easily implemented numerically. We carry out numerical experiments in both one and two space dimensions to verify this new algorithm.
Year
DOI
Venue
2010
10.1016/j.jcp.2010.06.026
J. Comput. Physics
Keywords
Field
DocType
delta function,level set method,partial transmission,schrödinger equation,finite sum,complete transmission,semiclassical limit,s. jin,schrodinger equation,interface,complete reflection,initial data,discontinuous potential,level set,initial value problem
Semiclassical physics,Discretization,Mathematical optimization,Classification of discontinuities,Mathematical analysis,Level set method,Schrödinger equation,Discontinuity (linguistics),Dirac delta function,Initial value problem,Mathematics
Journal
Volume
Issue
ISSN
229
19
Journal of Computational Physics
Citations 
PageRank 
References 
1
0.36
6
Authors
4
Name
Order
Citations
PageRank
Dongming Wei1133.54
Shi Jin257285.54
Richard Tsai39913.00
Xu Yang4459.17