[問題] 量力習題解惑

看板Physics作者 (BOOK)時間8年前 (2015/10/05 11:24), 編輯推噓0(003)
留言3則, 2人參與, 最新討論串1/1
【出處】量子力學習題 【題目】 Consider a particle governed by H = (-h^2/2m)d^2/dx^2+V(x). Now, if the particle is further confined to be at x = na with n be integers and a being a positive constant,one needs to discretize the system: replacing any function f(x = na) by fn and d^2/dx^2Ψ(x)∣x=na by [ (Ψn+1) + (Ψn-1) +2Ψn)] /a^2 . Let us denote the state when the particle is localized at x = na by ∣n> and assume that <n∣m>=δnm. Express H in terms of the Dirac notations. 【瓶頸】 題目要我把 H operator用Dirac notation表示. 他有提到要把系統discretized,但我不知道怎麼起頭, 也試著把 H operator ; f_n ; state ∣n> 連結在一起,不過都沒成功. 請各位版友可以給我提示讓我知道可以從何下手,感謝!! 小弟初學量力,請多包涵. -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 140.114.237.196 ※ 文章網址: https://www.ptt.cc/bbs/Physics/M.1444015475.A.0AD.html

10/05 12:06, , 1F
H = sum_{m,n} |m> <m|H|n> <n|
10/05 12:06, 1F

10/05 12:06, , 2F
所以…
10/05 12:06, 2F

10/06 17:24, , 3F
謝謝ker大的提示!
10/06 17:24, 3F
文章代碼(AID): #1M4Urp2j (Physics)