Successful Treatment of Refractory Atopic Dermatitis With the Use of High-Peak Power 1064 nm Nd:YAG Laser Therapy

Atopic dermatitis is a chronic inflammatory skin disease involving the complex association of genetic, immunologic, and environmental causes. Until recently, the treatment of eczematous processes was limited to the use of topical corticosteroids, systemic immunosuppressants, and controlling environmental triggers. Photobiotherapy offers a promising approach to the management of atopic dermatitis. Photobiotherapy is the clinical application of light for healing superficial wounds. We present 2 cases of patients with biopsy-proven, long-standing, poorly controlled atopic dermatitis successfully treated with a high-peak power 1064-nm neodynium:yttrium aluminum garnet (Nd:YAG) laser. Over the course of 9 years, each patient continued to undergo periodic laser treatments to maintain control over their disease. Both patients underwent a series of laser using high-peak power treatments with long-pulsed 1064-nm Nd:YAG laser (Cool Glide, Cutera, Brisbane, California) in “photorejuvenation/Genesis mode” over the course of 9 years. Case 1 received 29 treatments over a 9-year period. When financially able to, the patient had 1 treatment a month for 2 to 6 treatments a year. At the very least, she had a treatment during her worst flares. Case 2 received 19 treatments over 9 years with the timing being monthly when possible but with longer intervals between treatments if her disease was not flaring. One patient that was on systemic immunotherapy to control her atopic dermatitis was able to successfully come off this medication early in her treatment, and both patients experienced long-lasting improvement in their symptoms. The dramatic improvement in the skin eruption, symptoms, and quality of life in these patients further supports addition of the 300-µs 1064-nm Nd:YAG laser for the treatment of refractory atopic dermatitis. The authors are using this modality for less severe eczema that is refractory to topical therapies. However, a greater number of patients are needed as well as larger studies to further elucidate the mechanisms of lasers for eczematous processes. If further studies support this modality, it would be a safe alternative to systemic immunotherapies.

Rotational Doppler cooling and heating

Doppler cooling is a widely used technique to laser cool atoms, molecules, and nanoparticles by exploiting the Doppler shift associated with translational motion. The rotational Doppler effect arising from rotational coordinate transformation should similarly enable optical manipulation of the rotational motion of nanosystems. Here, we show that rotational Doppler cooling and heating (RDC and RDH) effects embody rich and unexplored physics, including an unexpected strong dependence on particle morphology. For geometrically constrained particles, cooling and heating are observed at red- or blue-detuned laser frequencies relative to particle resonances. In contrast, for nanosystems that can be modeled as solid particles, RDH appears close to resonant illumination, while detuned frequencies produce cooling of rotation. We further predict that RDH can lead to optomechanical spontaneous chiral symmetry breaking, where an achiral particle under linearly polarized illumination starts spontaneously rotating. Our results open up new exciting possibilities to control the rotational motion of nanosystems.

Cooling of a levitated nanoparticle to the motional quantum ground state

Quantum control of complex objects in the regime of large size and mass provides opportunities for sensing applications and tests of fundamental physics. The realization of such extreme quantum states of matter remains a major challenge. We demonstrate a quantum interface that combines optical trapping of solids with cavity-mediated light-matter interaction. Precise control over the frequency and position of the trap laser with respect to the optical cavity allowed us to laser-cool an optically trapped nanoparticle into its quantum ground state of motion from room temperature. The particle comprises 108 atoms, similar to current Bose-Einstein condensates, with the density of a solid object. Our cooling technique, in combination with optical trap manipulation, may enable otherwise unachievable superposition states involving large masses.

Two Cycling Centers in One Molecule: Communication by Through-Bond Interactions and Entanglement of the Unpaired Electrons

<div> <div> <div> <p>Many applications in quantum information science (QIS) rely on the ability to laser-cool molecules. The scope of applications can be expanded if laser-coolable molecules possess two or more cycling centers, i.e., moieties capable of scattering photons via multiple absorption-emission events. Here we employ equation-of-motion coupled-cluster method for double electron attachment (EOM-DEA-CCSD) to study electronic structure of hypermetallic molecules with two alkaline earth metals con- nected by an acetylene linker. We demonstrate that the interaction between two unpaired electrons is weak yet non-negligible, and is reflected in the underlying wavefunction. The electronic structure of the molecules is similar to that of two separated alkali metals, however the interaction between two electrons is largely dominated by through-bond interactions. The communication between the two cycling centers is quantified by the extent of the entanglement of the two unpaired electrons associated with each center. This contribution highlights rich electronic structure of hypermetallic molecules that may advance various applications in QIS and beyond. </p> </div> </div> </div>

Two Cycling Centers in One Molecule: Communication by Through-Bond Interactions and Entanglement of the Unpaired Electrons

<div> <div> <div> <p>Many applications in quantum information science (QIS) rely on the ability to laser-cool molecules. The scope of applications can be expanded if laser-coolable molecules possess two or more cycling centers, i.e., moieties capable of scattering photons via multiple absorption-emission events. Here we employ equation-of-motion coupled-cluster method for double electron attachment (EOM-DEA-CCSD) to study electronic structure of hypermetallic molecules with two alkaline earth metals con- nected by an acetylene linker. We demonstrate that the interaction between two unpaired electrons is weak yet non-negligible, and is reflected in the underlying wavefunction. The electronic structure of the molecules is similar to that of two separated alkali metals, however the interaction between two electrons is largely dominated by through-bond interactions. The communication between the two cycling centers is quantified by the extent of the entanglement of the two unpaired electrons associated with each center. This contribution highlights rich electronic structure of hypermetallic molecules that may advance various applications in QIS and beyond. </p> </div> </div> </div>

Towards a Rational Design of Laser-Coolable Molecules: Insights from Equation-of-Motion Coupled-Cluster Calculations

<div> <div> <div> <p>Access to cold molecules is critical for quantum information science, design of new sensors, ultracold chemistry, and search of new phenomena. These applications depend on the ability to laser-cool molecules. Theory and qualitative models can play a central role in narrowing down the vast pool of potential candidates amenable to laser cooling. We report a systematic study of structural and optical proper- ties of alkaline earth metal derivatives in the context of their applicability in laser cooling using equation-of-motion coupled-cluster methods. To rationalize and gen- eralize the results from high-level electronic structure calculations, we develop an effective Hamiltonian model. The model explains the observed trends and suggests new principles for the design of laser-coolable molecules. </p> </div> </div> </div>

Towards a Rational Design of Laser-Coolable Molecules: Insights from Equation-of-Motion Coupled-Cluster Calculations

<div> <div> <div> <p>Access to cold molecules is critical for quantum information science, design of new sensors, ultracold chemistry, and search of new phenomena. These applications depend on the ability to laser-cool molecules. Theory and qualitative models can play a central role in narrowing down the vast pool of potential candidates amenable to laser cooling. We report a systematic study of structural and optical proper- ties of alkaline earth metal derivatives in the context of their applicability in laser cooling using equation-of-motion coupled-cluster methods. To rationalize and gen- eralize the results from high-level electronic structure calculations, we develop an effective Hamiltonian model. The model explains the observed trends and suggests new principles for the design of laser-coolable molecules. </p> </div> </div> </div>