82 research outputs found
Engineering Dynamical Sweet Spots to Protect Qubits from 1/ Noise
Protecting superconducting qubits from low-frequency noise is essential for
advancing superconducting quantum computation. Based on the application of a
periodic drive field, we develop a protocol for engineering dynamical sweet
spots which reduce the susceptibility of a qubit to low-frequency noise. Using
the framework of Floquet theory, we prove rigorously that there are manifolds
of dynamical sweet spots marked by extrema in the quasi-energy differences of
the driven qubit. In particular, for the example of fluxonium biased slightly
away from half a flux quantum, we predict an enhancement of pure-dephasing by
three orders of magnitude. Employing the Floquet eigenstates as the
computational basis, we show that high-fidelity single- and two-qubit gates can
be implemented while maintaining dynamical sweet-spot operation. We further
confirm that qubit readout can be performed by adiabatically mapping the
Floquet states back to the static qubit states, and subsequently applying
standard measurement techniques. Our work provides an intuitive tool to encode
quantum information in robust, time-dependent states, and may be extended to
alternative architectures for quantum information processing
Analytical Review on Raloxifene -An Estrogen Receptor Modulator in Different Pharmaceutical Formulations and Biological Fluids
Raloxifene (RLX) is an oral selective estrogen receptor modulator (SERM). It is showing estrogenic action on bone and anti-estrogenic action on uterus and breast. An extensive literature has been published for analysis of RLX in different pharmaceutical formulations. This review article endeavor to provide the detail account on analytical methods for RLX and also validation details for its readers. It further helps to avoid costly chemicals and time consuming exercises for further investigation of RLX
Management of a case of laryngotracheal esophageal cleft type III with review of literature
Badole et al. Laryngotracheal esophageal cleft 80 Key points Laryngotracheal esophageal cleft (LTEC) is a rare developmental disorder of upper airway which accounts for 0.3% to 0.5% of all congenital anomalies of the larynx. It demands high clinical judgment to diagnose the case as most of the times patient is erroneously diagnosed as tracheoesophageal fistula and recurrent esophageal intubation or slipping of endotacheal tube in the esophagus should arise suspicion of LTEC. It has ben divided into four types by Benjamin and Inglis and severity depends upon type. Type III and IV present with severe symptoms in the neonatal period. Knowledge of different approaches to secure and maintain airway and preparedness for the same in such a case is most important to prevent catastrophic events
Combustion Behaviour of Advanced Solid Propellants.
The study reports the effect of incorporation of Al and ammonium perchlorate (AP) individually and in combination with each other on combustion pattern and specific impulse (Isp) of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions
Floquet-engineered enhancement of coherence times in a driven fluxonium qubit
We use the quasienergy structure that emerges when a fluxonium
superconducting circuit is driven periodically to encode quantum information
with dynamically induced flux-insensitive sweet spots. The framework of Floquet
theory provides an intuitive description of these high-coherence working points
located away from the half-flux symmetry point of the undriven qubit. This
approach offers flexibility in choosing the flux bias point and the energy of
the logical qubit states as shown in [\textit{Huang et al., 2020}]. We
characterize the response of the system to noise in the modulation amplitude
and DC flux bias, and experimentally demonstrate an optimal working point which
is simultaneously insensitive against fluctuations in both. We observe a
40-fold enhancement of the qubit coherence times measured with Ramsey-type
interferometry at the dynamical sweet spot compared with static operation at
the same bias point.Comment: 12 pages, 7 figure
Universal gates for protected superconducting qubits using optimal control
We employ quantum optimal control theory to realize quantum gates for two
protected superconducting circuits: the heavy-fluxonium qubit and the 0-
qubit. Utilizing automatic differentiation facilitates the simultaneous
inclusion of multiple optimization targets, allowing one to obtain
high-fidelity gates with realistic pulse shapes. For both qubits, disjoint
support of low-lying wave functions prevents direct population transfer between
the computational-basis states. Instead, optimal control favors dynamics
involving higher-lying levels, effectively lifting the protection for a
fraction of the gate duration. For the 0- qubit, offset-charge dependence
of matrix elements among higher levels poses an additional challenge for gate
protocols. To mitigate this issue, we randomize the offset charge during the
optimization process, steering the system towards pulse shapes insensitive to
charge variations. Closed-system fidelities obtained are 99% or higher, and
show slight reductions in open-system simulations.Comment: 12 pages, 6 figure
Accurate methods for the analysis of strong-drive effects in parametric gates
The ability to perform fast, high-fidelity entangling gates is an important
requirement for a viable quantum processor. In practice, achieving fast gates
often comes with the penalty of strong-drive effects that are not captured by
the rotating-wave approximation. These effects can be analyzed in simulations
of the gate protocol, but those are computationally costly and often hide the
physics at play. Here, we show how to efficiently extract gate parameters by
directly solving a Floquet eigenproblem using exact numerics and a perturbative
analytical approach. As an example application of this toolkit, we study the
space of parametric gates generated between two fixed-frequency transmon qubits
connected by a parametrically driven coupler. Our analytical treatment, based
on time-dependent Schrieffer-Wolff perturbation theory, yields closed-form
expressions for gate frequencies and spurious interactions, and is valid for
strong drives. From these calculations, we identify optimal regimes of
operation for different types of gates including SWAP, controlled-Z, and
CNOT. These analytical results are supplemented by numerical Floquet
computations from which we directly extract drive-dependent gate parameters.
This approach has a considerable computational advantage over full simulations
of time evolutions. More generally, our combined analytical and numerical
strategy allows us to characterize two-qubit gates involving parametrically
driven interactions, and can be applied to gate optimization and cross-talk
mitigation such as the cancellation of unwanted ZZ interactions in multi-qubit
architectures.Comment: 20 pages, 9 figures, 62 reference
Formulation Development, Evaluation and Comparative Study of Effects of Super Disintegrants in Cefixime Oral Disintegrating Tablets
The present work was aimed at formulation development, evaluation and comparative study of the effects of superdisintegrants in Cefixime 50 mg oral disintegrating tablets. The superdisintegrants used for the present study were sodium starch glycolate and crosscarmellose sodium. The formulated tablets were evaluated for various tableting properties, like hardness, thickness, friability, weight variation, disintegration time and dissolution rate. Comparative evaluation of the above-mentioned parameters established the superiority of the tablets formulated with crosscarmellose sodium to those formulated with sodium starch glycolate
- …