Mitiq : a software package for error mitigation on noisy quantum computers

We introduce Mitiq, a Python package for error mitigation on noisy quantum computers. Error mitigation techniques can reduce the impact of noise on near-term quantum computers with minimal overhead in quantum resources by relying on a mixture of quantum sampling and classical post-processing techniques. Mitiq is an extensible toolkit of different error mitigation methods, including zero-noise extrapolation, probabilistic error cancellation, and Clifford data regression. The library is designed to be compatible with generic backends and interfaces with different quantum software frameworks. We describe Mitiq using code snippets to demonstrate usage and discuss features and contribution guidelines. We present several examples demonstrating error mitigation on IBM and Rigetti superconducting quantum processors as well as on noisy simulators

A rhodamine embedded bio-compatible smart molecule mimicking a combinatorial logic circuit and ‘key-pad lock’ memory device for defending against information risk

Organic molecules with the possibility of logic operations are highly useful building blocks for the development of molecule-based ‘‘intelligent’’ devices for information processing applications. We have designed herein a very simple bio-friendly chemosensor (LC) equipped with a rhodamine fluorophore moiety. This probe showed a chromo-fluorescence response profile for Al3+ but a colorimetric response for Cu2+ metal. The absorption responses of LC caused by these metal ions along with the ‘‘OFF–ON– OFF’’ fluorescence behavior of an LC–Al3+ complex towards EDTA were employed for the development of a three-input and one output combinatorial molecular system. Interactions of the mentioned metal ions with LC in controlled sequential experiments gave fluorescence responses, enabling us to fabricate a ‘key-pad-logic’ function. So, a single molecular system performing such multiple ‘Boolean’ operations not only simplifies the complexity of a chemical driven ‘Intelligence’ device but also enriches the security of such a device against information invasion due to the sequence controlled sensor–analyte interactions and may find potential applications in biocompatible molecular logic platform

Morphology-Directing Synthesis of Rhodamine-Based Fluorophore Microstructures and Application toward Extra- and Intracellular Detection of Hg²⁺

A new, easily synthesizable rhodamine-based chemosensor with potential N₂O₂ donor atoms, <b>L</b>^<b>3</b>, has been characterized by single-crystal X-ray diffraction together with ¹H NMR and high-resolution mass spectrometry (HRMS) studies. <b>L</b>^<b>3</b> was found to bind selectively and reversibly to the highly toxic Hg²⁺ ion. The binding stoichiometry and formation constant of the sensor toward Hg²⁺ were determined by various techniques, including UV–vis, fluorescence, and Job’s studies, and substantiated by HRMS methods. None of the biologically relevant and toxic heavy metal ions interfered with the detection of Hg²⁺ ion. The limit of detection of Hg²⁺calculated by the 3σ method was 1.62 nM. The biocompatibility of <b>L</b>^<b>3</b> with respect to its good solubility in mixed organic/aqueous media (MeCN/H₂O) and cell permeability with no or negligible cytotoxicity provides good opportunities for in vitro/in vivo cell imaging studies. As the probe is poorly soluble in pure water, an attempt was made to frame nano/microstructures in the absence and in the presence of sodium dodecyl sulfate (SDS) as a soft template, which was found to be very useful in synthesizing morphologically interesting <b>L</b>^<b>3</b> microcrystals. In pure water, micro-organization of <b>L</b>^<b>3</b> indeed occurred with block-shaped morphology very similar to that in the presence of SDS as a template. However, when we added Hg²⁺ to the solution of <b>L</b>^<b>3</b> under the above two conditions, the morphologies of the microstructures were slightly different; in the first case, a flowerlike structure was observed, and in second case, a simple well-defined spherical microstructure was obtained. Optical microscopy revealed a dotlike microstructure for <b>L</b>^<b>3</b>–SDS assemblies, which changed to a panicle microstructure in the presence of Hg²⁺. UV–vis absorption and steady-state and time-resolved fluorescence studies were also carried out in the absence and presence of Hg²⁺, and also the SDS concentration was varied at fixed concentrations of the receptor and guest. The results revealed that the fluorescence intensity increased steadily with [SDS] until it became saturated at ∼7 mM SDS, indicating that the extent of perturbation to the emissive species increases with the increase in [SDS] until it becomes thermodynamically stable. There was also an increase in anisotropy with increasing SDS concentration, which clearly manifests the restriction of movement of the probe in the presence of SDS