SPONTANEOUS EMISSION BY MOVING ATOMS UNDERGOING TWO PHOTON-TRANSITION IN THE STRONG COUPLING REGIME

1996 ◽  
Vol 10 (19) ◽  
pp. 891-901
Author(s):  
AMITABH JOSHI
Keyword(s):  
Strong Coupling ◽  
Spontaneous Emission ◽  
Cavity Mode ◽  
Strong Coupling Regime ◽  
Mode Structure ◽  
Field Mode ◽  
Two Photon ◽  
Photon Transition ◽  
Fabry Perot ◽  
Excitation Probability

The dependence of spontaneous emission on atomic motion for an atom undergoing two-photon transition and moving along the axis of a Fabry-Perot cavity is analyzed here. For this purpose we consider the strong coupling limit of atom and cavity field mode and demonstrate the effects of atomic velocity and spatial mode structure of cavity mode on the excitation probability of atom.

Investigation of 6S 1/2–8S 1/2 two-photon transition of cesium atoms by a single 822 nm laser

2021 ◽  
Vol 19 (2) ◽  
pp. 025201
Author(s):  
Ning Liu ◽  
Sandan Wang ◽  
Jinpeng Yuan ◽  
Lirong Wang ◽  
Liantuan Xiao ◽  
...  
Keyword(s):  
Frequency Standard ◽  
Laser Beams ◽  
Fluorescence Signal ◽  
Frequency Reference ◽  
Two Photon ◽  
Photon Transition ◽  
Fabry Perot ◽  
Experimental Parameters ◽  
Stable Frequency ◽  
Vapor Temperature

Abstract We experimentally investigate the 6S 1/2–8S 1/2 two-photon transition in cesium vapor by a single laser. A blue (455.5 and 459.3 nm) fluorescence signal is observed as a result of 822.5 nm laser beams illuminating the Cs vapor with a counter-propagating configuration. The dependences of the fluorescence intensity on the polarization combinations of the laser beams, laser power and vapor temperature are studied to obtain optimal experimental parameters. The frequency difference between the two hyperfine components of 4158 (7) MHz is measured with a Fabry–Perot interferometer as a frequency reference. Such a large spectral isolation and the insensitivity to the Earth’s magnetic field enable the 6S 1/2–8S 1/2 transition to be a stable frequency standard candidate for a frequency-doubled 1644 nm laser in the U-band window for quantum telecommunication.

scholarly journals Boosting Self-interaction of Molecular Vibrations under Ultra-strong Coupling Condition

2021 ◽  
Author(s):  
Akhila Kadyan ◽  
Anil Shaji ◽  
Jino George
Keyword(s):  
Oscillator Strength ◽  
Strong Coupling ◽  
Cavity Mode ◽  
Linear Increase ◽  
Vacuum Field ◽  
New Paradigm ◽  
Coupling Condition ◽  
Field Coupling ◽  
Fabry Perot ◽  
Set Up

In this letter, we investigated the modification of oscillator strength of an asymmetric stretching band of CS<sub>2</sub> by strong coupling to an infrared cavity photon. This is achieved by placing liquid CS<sub>2</sub> in a Fabry-Perot resonator and tune the cavity mode position to match with the molecular vibrational transition. Ultra-strong coupling improves the self-interaction of transition dipoles of asymmetric stretching band of CS<sub>2</sub> that resulted in an increase of its own oscillator strength. We experimentally proved this by taking the area ratio of asymmetric stretching and combination band by selectively coupling the former one. A non-linear increase in the oscillator strength of the asymmetric stretching band is observed upon varying the coupling strength. This is explained by a quantum mechanical model that predicts quadratic behavior under ultra-strong coupling condition. These findings will set up a new paradigm for understanding chemical reaction modification by vacuum field coupling.

scholarly journals Cavity Catalysis ‒Accelerating Reactions under Vibrational Strong Coupling‒

2018 ◽  
Author(s):  
Hidefumi Hiura ◽  
Atef Shalabney ◽  
Jino George
Keyword(s):  
Electromagnetic Field ◽  
Strong Coupling ◽  
Chemical Reactions ◽  
Reaction Rate ◽  
Cavity Mode ◽  
Coupling Ratio ◽  
Strong Light ◽  
Rabi Splitting ◽  
Fabry Perot ◽  
Splitting Energy

<p>In conventional catalysis the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered and the reaction rate is accelerated. Here we take a radically different approach to catalysis by strongly coupling the vibrations of the reactants to the vacuum electromagnetic field of a cavity. To demonstrate the possibility of such cavity catalysis, we have studied hydrolysis reactions under strong coupling of the OH stretching mode of water to a Fabry-Pérot (FP) microfluidic cavity mode. This results in an exceptionally large Rabi splitting energy ℏΩ<sub>R</sub> of 92 meV (740 cm<sup>−1</sup>), indicating the system is in vibrational ultra-strong coupling (V-USC) regime and we have found that it enhances the hydrolysis reaction rate of cyanate ions by 10<sup>2</sup> times and that of ammonia borane by 10<sup>4</sup> times. This catalytic ability is shown to depend only upon the cavity tuning and the coupling ratio. Given the vital importance of water for life and human activities, we expect our finding not only offers an unconventional way of controlling chemical reactions by ultra-strong light-matter interactions, but also changes the landscape of chemistry in a fundamental way.</p>

SQUEEZING AND QUASIPROBABILITIES FOR A TWO-PHOTON JAYNES-CUMMINGS MODEL WITH ATOMIC MOTION

1992 ◽  
Vol 06 (21) ◽  
pp. 3539-3550 ◽  
Author(s):  
AMITABH JOSHI ◽  
SURESH V. LAWANDE
Keyword(s):  
Standard Model ◽  
Comparative Study ◽  
Interaction Time ◽  
Atomic Motion ◽  
Mode Structure ◽  
Field Mode ◽  
Two Photon ◽  
The Standard Model ◽  
Q Function ◽  
Quasiprobability Distribution

We study the squeezing and the quasiprobability distribution Q-function for an extended two-photon Jaynes-Cummings model (JCM) that includes atomic motion and the field mode structure. A comparative study of this model with respect to the standard model (in which the atom is at rest) has been presented here to isolate the effect of limited atom-radiation interaction time.

scholarly journals Cavity Catalysis ‒Accelerating Reactions under Vibrational Strong Coupling‒

2018 ◽  
Author(s):  
Hidefumi Hiura ◽  
Atef Shalabney ◽  
Jino George
Keyword(s):  
Electromagnetic Field ◽  
Strong Coupling ◽  
Chemical Reactions ◽  
Reaction Rate ◽  
Cavity Mode ◽  
Coupling Ratio ◽  
Strong Light ◽  
Rabi Splitting ◽  
Fabry Perot ◽  
Splitting Energy

<p>In conventional catalysis the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered and the reaction rate is accelerated. Here we take a radically different approach to catalysis by strongly coupling the vibrations of the reactants to the vacuum electromagnetic field of a cavity. To demonstrate the possibility of such cavity catalysis, we have studied hydrolysis reactions under strong coupling of the OH stretching mode of water to a Fabry-Pérot (FP) microfluidic cavity mode. This results in an exceptionally large Rabi splitting energy ℏΩ<sub>R</sub> of 92 meV (740 cm<sup>−1</sup>), indicating the system is in vibrational ultra-strong coupling (V-USC) regime and we have found that it enhances the hydrolysis reaction rate of cyanate ions by 10<sup>2</sup> times and that of ammonia borane by 10<sup>4</sup> times. This catalytic ability is shown to depend only upon the cavity tuning and the coupling ratio. Given the vital importance of water for life and human activities, we expect our finding not only offers an unconventional way of controlling chemical reactions by ultra-strong light-matter interactions, but also changes the landscape of chemistry in a fundamental way.</p>

scholarly journals Vacuum-Field Catalysis: Accelerated Reactions by Vibrational Ultra Strong Coupling

2019 ◽  
Author(s):  
Hidefumi Hiura ◽  
Atef Shalabney ◽  
Jino George
Keyword(s):  
Strong Coupling ◽  
Reaction Rate ◽  
Cavity Mode ◽  
Reaction Path ◽  
Vacuum Field ◽  
Coupling Ratio ◽  
Fabry Perot ◽  
Fresh Perspective ◽  
Light Matter Interaction ◽  
Splitting Energy

<p>In conventional catalysis, the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered by changing the reaction path, causing the reaction rate to be accelerated. Here we take a radically different<br>approach to catalysis by ultra-strongly coupling the vibrations of the reactants to the infrared vacuum electromagnetic field. To demonstrate the possibility of such<br>vacuum-field catalysis (or cavity catalysis), we have studied hydrolysis reactions under the vibrational ultra strong coupling (V-USC) of the OH stretching mode of water to a Fabry-Pérot microfluidic cavity mode. This results in a giant Rabi splitting energy (92 meV), indicating the system is in the V-USC regime. We have found that V-USC water enhances the hydrolysis reaction rate of cyanate ions by<br>10<sup>2</sup>-fold and that of ammonia borane by 10<sup>4</sup>-fold. This catalytic ability is found to depend upon the coupling ratio of the vibrational light-matter interaction. Given the vital importance of water for life and human activities, we expect that our finding not only offers an unconventional way of controlling chemical reactions by vacuum-field catalysis but also brings a fresh perspective to science and technology.</p>

scholarly journals Vacuum-Field Catalysis: Accelerated Reactions by Vibrational Ultra Strong Coupling

2021 ◽  
Author(s):  
Hidefumi Hiura ◽  
Atef Shalabney
Keyword(s):  
Strong Coupling ◽  
Reaction Rate ◽  
Cavity Mode ◽  
Reaction Path ◽  
Vacuum Field ◽  
Coupling Ratio ◽  
Fabry Perot ◽  
Fresh Perspective ◽  
Light Matter Interaction ◽  
Splitting Energy

<p>In conventional catalysis, the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered by changing the reaction path, causing the reaction rate to be accelerated. Here we take a radically different<br>approach to catalysis by ultra-strongly coupling the vibrations of the reactants to the infrared vacuum electromagnetic field. To demonstrate the possibility of such<br>vacuum-field catalysis (or cavity catalysis), we have studied hydrolysis reactions under the vibrational ultra strong coupling (V-USC) of the OH stretching mode of water to a Fabry-Pérot microfluidic cavity mode. This results in a giant Rabi splitting energy (92 meV), indicating the system is in the V-USC regime. We have found that V-USC water enhances the hydrolysis reaction rate of cyanate ions by<br>10<sup>2</sup>-fold and that of ammonia borane by 10<sup>4</sup>-fold. This catalytic ability is found to depend upon the coupling ratio of the vibrational light-matter interaction. Given the vital importance of water for life and human activities, we expect that our finding not only offers an unconventional way of controlling chemical reactions by vacuum-field catalysis but also brings a fresh perspective to science and technology.</p>

scholarly journals Boosting Self-interaction of Molecular Vibrations under Ultra-strong Coupling Condition

2021 ◽  
Author(s):  
Akhila Kadyan ◽  
Anil Shaji ◽  
Jino George
Keyword(s):  
Oscillator Strength ◽  
Strong Coupling ◽  
Cavity Mode ◽  
Linear Increase ◽  
Vacuum Field ◽  
New Paradigm ◽  
Coupling Condition ◽  
Field Coupling ◽  
Fabry Perot ◽  
Set Up

In this letter, we investigated the modification of oscillator strength of an asymmetric stretching band of CS<sub>2</sub> by strong coupling to an infrared cavity photon. This is achieved by placing liquid CS<sub>2</sub> in a Fabry-Perot resonator and tune the cavity mode position to match with the molecular vibrational transition. Ultra-strong coupling improves the self-interaction of transition dipoles of asymmetric stretching band of CS<sub>2</sub> that resulted in an increase of its own oscillator strength. We experimentally proved this by taking the area ratio of asymmetric stretching and combination band by selectively coupling the former one. A non-linear increase in the oscillator strength of the asymmetric stretching band is observed upon varying the coupling strength. This is explained by a quantum mechanical model that predicts quadratic behavior under ultra-strong coupling condition. These findings will set up a new paradigm for understanding chemical reaction modification by vacuum field coupling.

scholarly journals Vacuum-Field Catalysis: Accelerated Reactions by Vibrational Ultra Strong Coupling

2019 ◽  
Author(s):  
Hidefumi Hiura ◽  
Atef Shalabney ◽  
Jino George
Keyword(s):  
Strong Coupling ◽  
Reaction Rate ◽  
Cavity Mode ◽  
Reaction Path ◽  
Vacuum Field ◽  
Coupling Ratio ◽  
Fabry Perot ◽  
Fresh Perspective ◽  
Light Matter Interaction ◽  
Splitting Energy

<p>In conventional catalysis, the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered by changing the reaction path, causing the reaction rate to be accelerated. Here we take a radically different<br>approach to catalysis by ultra-strongly coupling the vibrations of the reactants to the infrared vacuum electromagnetic field. To demonstrate the possibility of such<br>vacuum-field catalysis (or cavity catalysis), we have studied hydrolysis reactions under the vibrational ultra strong coupling (V-USC) of the OH stretching mode of water to a Fabry-Pérot microfluidic cavity mode. This results in a giant Rabi splitting energy (92 meV), indicating the system is in the V-USC regime. We have found that V-USC water enhances the hydrolysis reaction rate of cyanate ions by<br>10<sup>2</sup>-fold and that of ammonia borane by 10<sup>4</sup>-fold. This catalytic ability is found to depend upon the coupling ratio of the vibrational light-matter interaction. Given the vital importance of water for life and human activities, we expect that our finding not only offers an unconventional way of controlling chemical reactions by vacuum-field catalysis but also brings a fresh perspective to science and technology.</p>

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