翻訳と辞書 Words near each other ・ Singlesex ・ Singlesexed ・ Singlesexes ・ Singlesexing ・ Singleship ・ Singlesidedness ・ Singlesider ・ Singlesiders ・ Singlesides ・ Singlesiding ・ Singlesidings ・ Singlestick ・ Singlet ・ Singlet fission ・ Singlet oxygen ・ Singlet state ・ Singletary ・ Singletary Center for the Arts ・ Singletary Lake ・ Singletary Lake State Park ・ Singletary-Reese-Robinson House ・ Singleton ・ Singleton (global governance) ・ Singleton (Lancashire) railway station ・ Singleton (lifestyle) ・ Singleton (mathematics) ・ Singleton (West Sussex) railway station ・ Singleton Abbey ・ Singleton Bank rail crash ・ Singleton bound Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Singlet state ： ウィキペディア英語版 Singlet state In quantum mechanics, a singlet is a quantum state of a system with a spin of 0, such that there is only one allowed value of the spin component, 0. A pair of spin-1/2 particles can be combined to form one of three states of total spin 1 called the triplet, or a state of spin 0 which is called the singlet.〔D. J. Griffiths, ''Introduction to Quantum Mechanics'', Prentice Hall, Inc., 1995, pg. 165.〕 In theoretical physics, a singlet usually refers to a one-dimensional representation (e.g. a particle with vanishing spin). It may also refer to two or more particles prepared in a co-related state, such that the total angular momentum of the state is zero. Singlets and other such representations frequently occur in atomic physics and nuclear physics, where one tries to determine the total spin from a collection of particles. A single electron has spin 1/2, and upon rotation its state transforms as a doublet, that is, as the fundamental representation of the Lie group SU(2).〔J. J. Sakurai, Modern Quantum Mechanics, Addison Wesley, 1985.〕 We can measure the spin of this electron's state by applying an operator $\backslash vec^2$ to the state, and we will always obtain $\backslash hbar^2\; \backslash ,\; (1/2)\; \backslash ,\; (1/2\; +\; 1)\; =\; (3/4)\; \backslash ,\; \backslash hbar^2$ (or spin 1/2) since the spin-up and spin-down states are both eigenstates of this operator with the same eigenvalue. Likewise, if we have a system of two electrons, we can measure the total spin by applying $\backslash left(\backslash vec\_1\; +\; \backslash vec\_2\backslash right)^2$, where $\backslash vec\_1$ acts on electron 1 and $\backslash vec\_2$ acts on electron 2. However, we can now have two possible spins, which is to say, two possible eigenvalues of the total spin operator, corresponding to spin-0 or spin-1. Each eigenvalue belongs to a set of eigenstates. The "spin-0" set is called the singlet, containing one state (see below), and the "spin-1" set is called the triplet, containing three possible eigenstates. In more mathematical language, we say the product of two doublet representations can be decomposed into the sum of the adjoint representation (the triplet) and the trivial representation, the singlet. The singlet state formed from a pair of electrons has many peculiar properties, and plays a fundamental role in the EPR paradox and quantum entanglement. In Dirac notation this EPR state is usually represented as: :$\backslash frac\{\backslash sqrt\{2\}\}\backslash left(\; \backslash left|\backslash uparrow\; \backslash downarrow\; \backslash right\backslash rangle\; -\; \backslash left|\backslash downarrow\; \backslash uparrow\; \backslash right\backslash rangle\backslash right)$ == References == 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Singlet state」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.