Dynamics of the Cavity Radiation of a Correlated Emis-sion Laser Coupled to a Two-Mode Thermal Reservoir

In this paper, the quantum properties of the cavity light beam produced by a coherently driven nondegenerate three-level laser with an open cavity and coupled to a two-mode thermal reservoir are thoroughly analyzed. We have carried out our analysis by putting the noise operators associated with the thermal reservoir in normal order. Here we discussed more the effect of thermal light and the spontaneous emission on the dynamics of the quantum processes. It is found that the maximum degree of intracavity squeezing 43% below the vacuum-state level. Moreover, the presence of thermal light leads to decrease the degree of entanglement.

The Effect of Superposition on the Quantum Features of the Cavity Radiation of a Three-Level Laser

We study the statistical and squeezing properties of the cavity light produced by a degenerate three-level laser with the use of the solution of the pertinent quantum Langevin equation. Moreover, applying the density operator to the cavity radiation superposition, we investigated the quantum properties of the superposed cavity light beams generated by a pair of degenerate three-level lasers. Superposing the cavity radiation increases the mean and the variance of the photon number without affecting the quadrature squeezing. It is observed that the degree of squeezing of the separate cavity radiation, as well as the superposed cavity radiation, increases with the rate at which the atoms are injected into the cavity. We have also shown that the mean photon number of the superposed cavity radiation is the sum of the mean photon numbers of the individual cavity radiation. However, the variance of the photon number of the superposed cavity radiation turns out to be four times that of the component cavity radiation.

Quantum Entanglement and its Quantification in a Two-Mode Cascade Laser

In this paper, quantum entanglement of correlated two-mode light generated by a three-level laser coupled to a two-mode squeezed vacuum reservoir is thoroughly analyzed using different inseparability criteria, using the master equation, we obtain the stochastic dierential equation and the correlation properties of the noise forces associated with the normal ordering. Next, we study the photon entanglement by considering different inseparability criteria. In particular, the criteria applied are Duan-Giedke-Cirac-Zoller (DGCZ) criterion, logarithmic negativity, Hillery-Zubairy, and Cauchy-Schwartz inequality and we found that the presence of the squeezing parameter leads to an increase in the degree of entanglement. Moreover, the linear gain coecient significantly achieved the degree of entanglement for the cavity radiation

Generation of Entangled Light from a Nondegenerate Three-Level Laser Coupled to a Two-Mode Vacuum Reservoir

The quantum properties of a nondegenerate three-level cascade laser coupled to a two-mode vacuum reservoir are throughly analyzed with the use of the pertinent master equation and stochastic differential equations associated with the normal ordering. Particularly, the enhancement of squeezing and the amplification of photon entanglement of the two-mode cavity light are investigated. It is found that the two cavity modes are strongly entangled, and the degree of entanglement is directly related to the two-mode squeezing. Moreover, the squeezing and entanglement of the cavity radiation enhance with the rate of atomic injection.

RADI-10. Is there any benefit for post-operative radiation in brain metastases? A systematic review and meta-analysis of Randomized controlled trials

Purpose The benefits of adding upfront post-operative radiation (either whole-brain or cavity radiation) have been debated, particularly due to the possible detriment in cognition post-radiation. We sought to compare the efficacy and safety between the surgical resection of brain metastases (BM) plus radiotherapy versus surgical resection alone. Materials and Methods We searched various biomedical databases from 1983 to 2019, for eligible randomized controlled trials (RCT). Outcomes studied were local recurrence (LR), overall survival (OS), and serious (Grade 3 +) adverse events (AE). We used the random-effects model to pool outcomes. The methodological quality of each study was assessed using the Cochrane Risk of Bias tool. Results We included 5 RCTs comprising of 673 patients. The odds ratio (OR) for LR ranged from 0.06–0.34 with a pooled odds ratio of 0.26 (95% confidence interval (CI) 0.19–0.37, P< 0.001), strongly favoring the patients who received postoperative radiation. The overall survival (OS) was only reported in 3 studies and did not show any significant difference. The hazard ratio (HR) ranged from 1.01–1.29 with a pooled HR of 1.1 (95% CI 0.90–1.34, P=0.37). The treatment-related toxicities were inconsistently reported to draw any meaningful conclusions. The risk of bias was predominantly due to the lack of blinding and was deemed to be high, affecting all outcomes. Conclusion Our analysis confirms that postoperative radiation should be recommended after surgical resection of BM, for it significantly reduces the risk of local recurrence. However, we did not find any improvement in OS, suggesting that improvements in local control at the tumor bed alone may not impact survival. Balancing local control, and possible neuro-cognitive effects of whole-brain radiation, post-operative cavity radiation seems to be an attractive option.

Characterization of a Two-Photon Quantum Battery: Initial Conditions, Stability and Work Extraction

We consider a quantum battery that is based on a two-level system coupled with a cavity radiation by means of a two-photon interaction. Various figures of merit, such as stored energy, average charging power, energy fluctuations, and extractable work are investigated, considering, as possible initial conditions for the cavity, a Fock state, a coherent state, and a squeezed state. We show that the first state leads to better performances for the battery. However, a coherent state with the same average number of photons, even if it is affected by stronger fluctuations in the stored energy, results in quite interesting performance, in particular since it allows for almost completely extracting the stored energy as usable work at short enough times.

Enhancing Steady-State Entanglement Generated by a Nondegenerate Three-Level Laser with Thermal Reservoir

We analyze a nondegenerate three-level cascade laser with an open cavity and coupled to a two-mode thermal reservoir employing the stochastic differential equations for atomic operators associated with the normal ordering. Applying the large-time approximation scheme, we obtain the solutions for the corresponding equations of evolution of the expectation values of atomic operators. Furthermore, employing the resulting solutions, we studied the photon as well as cavity atomic-state entanglement amplification of the cavity radiation.