*et al.*[

Search by keywords or author

- Photonics Research
- Vol. 8, Issue 11, 1783 (2020)

Abstract

The model introduced in Ref. [*et al.* consists of two adjacent molecules placed in the hot spot of a plasmonic cavity, which directly interact through dipole–dipole interaction and are also driven by two color laser beams (i.e., a strong pump and a weak probe laser), as shown in Fig. *i*), $\lambda $ is the dipole–dipole coupling constant, ${\delta}_{\text{pu}}={\omega}_{c}-{\omega}_{\text{pu}}$ is pump cavity detuning, ${g}_{i}$ is optomechanical coupling constant, and ${\mathrm{\Omega}}_{\text{pu}},\text{\hspace{0.17em}}{\mathrm{\Omega}}_{\text{pr}}$ are the laser pumping and probing rate, respectively. Using the Lindblad master equation, the dynamical behavior of open whole systems can investigate as follows [

Figure 1.Schematic of the model and relevant parameters.

Although two molecules are coupled to a common heat bath at temperature ${T}_{\mathrm{bath}}$ (authors had considered room temperature, i.e., ${T}_{\mathrm{bath}}=300\text{\hspace{0.17em}\hspace{0.17em}}\mathrm{K}$), optomechanical interaction between molecules and dipole–dipole can modify the temperature of molecules. Hence, we define the effective mean phonon number as where ${\rho}_{\mathrm{ss}}$ is the steady-state density operator. As a direct result, the effective temperature of each molecule yields [

Figure 2.Effective temperature of molecules as a function of optomechanical coupling constants (notice that all parameters are considered similar to the main paper, i.e.,

Now, we provide a corrected formula for estimation of the root mean square (rms) amplitude of molecular motion and show that the equipartition theorem does not work in molecular optomechanics systems in contrast with the common optomechanical system. The rms amplitude of molecular motion is defined as follows: where ${m}_{\mathrm{e}\mathrm{f}\mathrm{f}}$ is considered as the effective mass of the benzene ring and the atom of sulfur or gold for molecules of thiophenol or GBT $({m}_{\mathrm{e}\mathrm{f}\mathrm{f}}\approx 3.6\times {10}^{-26}\text{\hspace{0.17em}}\mathrm{k}\mathrm{g})$ [

Sign up for ** Photonics Research** TOC. Get the latest issue of

Figure 3.Comparison between different methods (equipartition theorem, numerical, and corrected formula) for minimal measurable force as a function of molecular frequency, with two different effective temperatures.

In particular, we achieve the rms of molecules GBT in the main paper at effective temperature (${T}_{i}^{\mathrm{eff}}\approx 320$ K) using our correct formula [Eq. (

Acknowledgment

**Acknowledgment**. I would like to express my special appreciation and thanks to my advisor Dr. Johannes Feist for assistance with developing our revised paper.

References

[2] H.-P. Breuer, F. Petruccione**. The Theory of Open Quantum Systems(2002)**.

Seyed Mahmoud Ashrafi, Narjes Taghadomi, Alireza Bahrampour, Rasoul Malekfar. Coupled quantum molecular cavity optomechanics with surface plasmon enhancement: comment[J]. Photonics Research, 2020, 8(11): 1783

Download Citation

Set citation alerts for the article

Please enter your email address