Stable Boron-Containing Blue-Photoluminescent Radicals

<div>It is highly urgent to develop synthetic strategies to make new category of stable luminescent radicals with desired emission wavelength. In this study, we have isolated two dioxoborocyclic radicals ( <b>3</b> and <b>4</b> ) by a direct sy nthetic rou te. They were charac terized by UV, EPR spectroscopy and SQUID measurements. Their structures were obtained by single crystal X ray diffraction. Both radicals produce blue photoluminescence (458 nm for <b>3</b> and 478 nm for <b>4</b> ) by radiative decay from higher excited states (D₂/D₃) to the ground state (D₀) based on theoretical calculation, breaking Kasha rule. The work records a new kind of radical emitters and the first stable radicals with blue emission bands.</div>

Stable Boron-Containing Blue-Photoluminescent Radicals

<div>It is highly urgent to develop synthetic strategies to make new category of stable luminescent radicals with desired emission wavelength. In this study, we have isolated two dioxoborocyclic radicals ( <b>3</b> and <b>4</b> ) by a direct sy nthetic rou te. They were charac terized by UV, EPR spectroscopy and SQUID measurements. Their structures were obtained by single crystal X ray diffraction. Both radicals produce blue photoluminescence (458 nm for <b>3</b> and 478 nm for <b>4</b> ) by radiative decay from higher excited states (D₂/D₃) to the ground state (D₀) based on theoretical calculation, breaking Kasha rule. The work records a new kind of radical emitters and the first stable radicals with blue emission bands.</div>

Spectroscopic study of EUV and SXR spectral lines with partition function and level population of W LVI

We present comprehensive and elaborate study of W LVI (K-likeW55+) by using multi-configuration Dirac-Fock method (MCDF). We have included relativistic corrections, QED (Quantum electrodynamics) and Breit corrections in our computation. We have reported energy levels and radiative data for multipole transitions i.e. electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) within lowest 142 fine structure levels and predicted soft x-ray transition (SXR) and extreme ultraviolet transitions (EUV) from higher excited states to ground state. We have compared our calculated data with energy levels compiled by NIST and other available results in literature and small discrepancies found with them are discussed. Since only few lowest levels are only available in the literature, therefore for checking excitation energies of higher excited states, we have performed same calculations with distorted wave method. Furthermore, we have also provided relative population for first five excited states, partition function and thermodynamic quantities for both W LVI and studied their variations with temperature. We believe that our reported new atomic data of W LVI may be useful in identification and analysis of spectral lines from various astrophysical and fusion plasma sources and also beneficial in plasma modeling.

State leakage during fast decay and control of a superconducting transmon qubit

Superconducting Josephson junction qubits constitute the main current technology for many applications, including scalable quantum computers and thermal devices. Theoretical modeling of such systems is usually done within the two-level approximation. However, accurate theoretical modeling requires taking into account the influence of the higher excited states without limiting the system to the two-level qubit subspace. Here, we study the dynamics and control of a superconducting transmon using the numerically exact stochastic Liouville–von Neumann equation approach. We focus on the role of state leakage from the ideal two-level subspace for bath induced decay and single-qubit gate operations. We find significant short-time state leakage due to the strong coupling to the bath. We quantify the leakage errors in single-qubit gates and demonstrate their suppression with derivative removal adiabatic gates (DRAG) control for a five-level transmon in the presence of decoherence. Our results predict the limits of accuracy of the two-level approximation and possible intrinsic constraints in qubit dynamics and control for an experimentally relevant parameter set.