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Nov 10, 2023 at 9:24 comment added Shoaib Mirzaei You used Displacement operator $D(\alpha) = exp(\alpha a^\dagger)$ to convert $|\alpha>$ into $|0>$, but $D(|\alpha>) = exp(\alpha a^\dagger - \alpha^* a)$. what happened to annihilation operator?
Aug 5, 2023 at 15:27 comment added SolubleFish If $A$ is a matrix or an operator, its exponential is defined by the Taylor series : $\exp(\hat A) = \sum_{n=0}^{+\infty} \frac{1}{n!} \hat A^n$. Since we have $\left(\hat A^n\right)^\dagger =\left(\hat A^\dagger\right)^n$, we get $\exp\left(\hat A^\dagger\right) = \exp\left(\hat A^\dagger\right)$. (Note that this work for any analytic function whose Taylor coefficients are real.)
Jul 26, 2023 at 15:36 comment added Shoaib Mirzaei @SolubleFish, Thanks for this brilliant answer, but can you describe how you put T and T^\dagger inside exponential?
May 12, 2022 at 5:07 vote accept asd.123
May 10, 2022 at 17:19 comment added SolubleFish Yes, I took the liberty to abuse notation and write $|0\rangle$ in place of $|0\rangle \otimes |0\rangle$ for the ground state.
May 10, 2022 at 16:48 comment added asd.123 Thanks a lot, but I have tried to replicate your work and realized that it should be $|\alpha\rangle \otimes|\beta\rangle=\exp \left(-\frac{|\alpha|^{2}+|\beta|^2}{2}\right) \exp \left(\alpha \hat{a}_{i}^{\dagger}+\beta \hat{b}_{i}^{\dagger}\right)|0\rangle\otimes|0\rangle$ for second line, can you check it?
May 10, 2022 at 16:00 history answered SolubleFish CC BY-SA 4.0