### 1326 results for qubit oscillator frequency

Contributors: Eugene Grichuk, Margarita Kuzmina, Eduard Manykin

Date: 2010-09-26

A network of coupled stochastic **oscillators** is
proposed for modeling of a cluster of entangled **qubits** that is
exploited as a computation resource in one-way quantum
computation schemes. A **qubit** model has been designed as a
stochastic **oscillator** formed by a pair of coupled limit cycle
**oscillators** with chaotically modulated limit cycle radii and
**frequencies**. The **qubit** simulates the behavior of electric field of
polarized light beam and adequately imitates the states of two-level
quantum system. A cluster of entangled **qubits** can be associated
with a beam of polarized light, light polarization degree being
directly related to cluster entanglement degree. Oscillatory network,
imitating **qubit** cluster, is designed, and system of equations for
network dynamics has been written. The constructions of one-**qubit**
gates are suggested. Changing of cluster entanglement degree caused
by measurements can be exactly calculated....network of stochastic **oscillators** ... A network of coupled stochastic **oscillators** is
proposed for modeling of a cluster of entangled **qubits** that is
exploited as a computation resource in one-way quantum
computation schemes. A **qubit** model has been designed as a
stochastic **oscillator** formed by a pair of coupled limit cycle
**oscillators** with chaotically modulated limit cycle radii and
**frequencies**. The **qubit** simulates the behavior of electric field of
polarized light beam and adequately imitates the states of two-level
quantum system. A cluster of entangled **qubits** can be associated
with a beam of polarized light, light polarization degree being
directly related to cluster entanglement degree. Oscillatory network,
imitating **qubit** cluster, is designed, and system of equations for
network dynamics has been written. The constructions of one-**qubit**
gates are suggested. Changing of cluster entanglement degree caused
by measurements can be exactly calculated.

Files:

Contributors: Ying-Jie Chen, Hai-Tao Song, Jing-Lin Xiao

Date: 2017-10-14

Temperature effects on polaron in triangular quantum dot **qubit** subjected to an electromagnetic field are studied.
We derive the numerical results and formulate the derivative relationships of the ground and first
excited state energies, the electron probability density and the electron **oscillating** period in the superposition state of
the ground state and the first-excited state with the temperature, the cyclotron **frequency**, the electron-phonon coupling
constant, the electric field strength, the confinement strength and the Coulomb impurity potential, respectively....6-The electron **oscillating** period as functions of the temperature and the cyclotron **frequency** in triangular quantum dot **qubit** under an electric field.docx...7-The electron **oscillating** period as functions of the temperature and the electron-phonon coupling constant and etc. in triangular quantum dot **qubit** under an electric field.docx...2-The first excited state energy as functions of the temperature and the cyclotron **frequency** in triangular quantum dot **qubit** under an electric field.docx...3-The ground state energy as functions of the temperature and the electron-phonon coupling constant and etc. in triangular quantum dot **qubit** under an electric field.docx...1-The ground state energy as functions of the temperature and the cyclotron **frequency** in triangular quantum dot **qubit** under an electric field.docx ... Temperature effects on polaron in triangular quantum dot **qubit** subjected to an electromagnetic field are studied.
We derive the numerical results and formulate the derivative relationships of the ground and first
excited state energies, the electron probability density and the electron **oscillating** period in the superposition state of
the ground state and the first-excited state with the temperature, the cyclotron **frequency**, the electron-phonon coupling
constant, the electric field strength, the confinement strength and the Coulomb impurity potential, respectively.

Files:

Contributors: Yan, Ying, Li, Yichao, Kinos, Adam, Walther, Andreas, Shi, Chunyan, Rippe, Lars, Moser, Joel, Kröll, Stefan, Chen, Xi

Date: 2019-03-18

Inverse engineering of shortcut pulses for high fidelity initialization on **qubits** closely spaced in **frequency**...High-fidelity **qubit** initialization is of significance for efficient error correction in fault tolerant quantum algorithms. Combining two best worlds, speed and robustness, to achieve high-fidelity state preparation and manipulation is challenging in quantum systems, where **qubits** are closely spaced in **frequency**. Motivated by the concept of shortcut to adiabaticity, we theoretically propose the shortcut pulses via inverse engineering and further optimize the pulses with respect to systematic errors in **frequency** detuning and Rabi **frequency**. Such protocol, relevant to **frequency** selectivity, is applied to rare-earth ions **qubit** system, where the excitation of **frequency**-neighboring **qubits** should be prevented as well. Furthermore, comparison with adiabatic complex hyperbolic secant pulses shows that these dedicated initialization pulses can reduce the time that ions spend in the excited state by a factor of 6, which is important in coherence time limited systems to approach an error rate manageable by quantum error correction. The approach may also be applicable to superconducting **qubits**, and any other systems where **qubits** are addressed in **frequency**. ... High-fidelity **qubit** initialization is of significance for efficient error correction in fault tolerant quantum algorithms. Combining two best worlds, speed and robustness, to achieve high-fidelity state preparation and manipulation is challenging in quantum systems, where **qubits** are closely spaced in **frequency**. Motivated by the concept of shortcut to adiabaticity, we theoretically propose the shortcut pulses via inverse engineering and further optimize the pulses with respect to systematic errors in **frequency** detuning and Rabi **frequency**. Such protocol, relevant to **frequency** selectivity, is applied to rare-earth ions **qubit** system, where the excitation of **frequency**-neighboring **qubits** should be prevented as well. Furthermore, comparison with adiabatic complex hyperbolic secant pulses shows that these dedicated initialization pulses can reduce the time that ions spend in the excited state by a factor of 6, which is important in coherence time limited systems to approach an error rate manageable by quantum error correction. The approach may also be applicable to superconducting **qubits**, and any other systems where **qubits** are addressed in **frequency**.

Contributors: Duddell, William

Date: 1908-10-31

... n/a

Files:

Contributors: White, William C.

Date: 1916-10-01

... n/a

Files:

Contributors: Martin Vreugdenhil, John G R Jefferys, Peter D Ward, Olaleke O Oke, Andor Magony, Himashi Anver, Premysl Jiruska

Date: 2010-01-01

Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band **frequencies** (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-**frequency** gamma **oscillations** remain unknown. In rat visual cortex slices, kainate and carbachol induce high-**frequency** gamma **oscillations** (fast-gamma; peak **frequency** approximately 80 Hz at 37 degrees C) that can coexist with low-**frequency** gamma **oscillations** (slow-gamma; peak **frequency** approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) **oscillations** generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their **frequencies** were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their **frequencies** were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-**frequency** gamma **oscillations**. ... Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band **frequencies** (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-**frequency** gamma **oscillations** remain unknown. In rat visual cortex slices, kainate and carbachol induce high-**frequency** gamma **oscillations** (fast-gamma; peak **frequency** approximately 80 Hz at 37 degrees C) that can coexist with low-**frequency** gamma **oscillations** (slow-gamma; peak **frequency** approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) **oscillations** generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their **frequencies** were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their **frequencies** were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-**frequency** gamma **oscillations**.

Files:

Contributors: Drausin Wulsin, Brian Litt, Allison Pearce, Justin A Blanco, Abba Krieger, William C Stacey

Date: 2013-01-01

Counts of high-**frequency** **oscillations** (HFOs) in each time epoch for dispersion analysis. Preictal and postictal epochs were defined as 10 min before and after seizures, respectively....High-**frequency** (100-500 Hz) **oscillations** (HFOs) recorded from intracranial electrodes are a potential biomarker for epileptogenic brain. HFOs are commonly categorized as ripples (100-250 Hz) or fast ripples (250-500 Hz), and a third class of mixed **frequency** events has also been identified. We hypothesize that temporal changes in HFOs may identify periods of increased the likelihood of seizure onset. HFOs (86,151) from five patients with neocortical epilepsy implanted with hybrid (micro + macro) intracranial electrodes were detected using a previously validated automated algorithm run over all channels of each patient's entire recording. HFOs were characterized by extracting quantitative morphologic features and divided into four time epochs (interictal, preictal, ictal, and postictal) and three HFO clusters (ripples, fast ripples, and mixed events). We used supervised classification and nonparametric statistical tests to explore quantitative changes in HFO features before, during, and after seizures. We also analyzed temporal changes in the rates and proportions of events from each HFO cluster during these periods. We observed patient-specific changes in HFO morphology linked to fluctuation in the relative rates of ripples, fast ripples, and mixed **frequency** events. These changes in relative rate occurred in pre- and postictal periods up to thirty min before and after seizures. We also found evidence that the distribution of HFOs during these different time periods varied greatly between individual patients. These results suggest that temporal analysis of HFO features has potential for designing custom seizure prediction algorithms and for exploring the relationship between HFOs and seizure generation. ... High-**frequency** (100-500 Hz) **oscillations** (HFOs) recorded from intracranial electrodes are a potential biomarker for epileptogenic brain. HFOs are commonly categorized as ripples (100-250 Hz) or fast ripples (250-500 Hz), and a third class of mixed **frequency** events has also been identified. We hypothesize that temporal changes in HFOs may identify periods of increased the likelihood of seizure onset. HFOs (86,151) from five patients with neocortical epilepsy implanted with hybrid (micro + macro) intracranial electrodes were detected using a previously validated automated algorithm run over all channels of each patient's entire recording. HFOs were characterized by extracting quantitative morphologic features and divided into four time epochs (interictal, preictal, ictal, and postictal) and three HFO clusters (ripples, fast ripples, and mixed events). We used supervised classification and nonparametric statistical tests to explore quantitative changes in HFO features before, during, and after seizures. We also analyzed temporal changes in the rates and proportions of events from each HFO cluster during these periods. We observed patient-specific changes in HFO morphology linked to fluctuation in the relative rates of ripples, fast ripples, and mixed **frequency** events. These changes in relative rate occurred in pre- and postictal periods up to thirty min before and after seizures. We also found evidence that the distribution of HFOs during these different time periods varied greatly between individual patients. These results suggest that temporal analysis of HFO features has potential for designing custom seizure prediction algorithms and for exploring the relationship between HFOs and seizure generation.

Files:

Contributors: Abdul-Niby, M., Alameen, M., Baitie, H.

Date: 2016-12-18

injection locked **oscillator**...In Self **Oscillating** systems, locking of the **oscillators** can take place for injected signals close in **frequency** to nth harmonics of the free-running **frequency**. In this paper, we present a simple design for digital phase shift control by using a harmonically injection locked **oscillator** (ILO) of 35MHz **frequency**. Phase shifters at high **frequencies** are essential in many communication system applications such as **frequency** synthesis, quadrature signal generation and phase locked loops (PLLs).
... In Self **Oscillating** systems, locking of the **oscillators** can take place for injected signals close in **frequency** to nth harmonics of the free-running **frequency**. In this paper, we present a simple design for digital phase shift control by using a harmonically injection locked **oscillator** (ILO) of 35MHz **frequency**. Phase shifters at high **frequencies** are essential in many communication system applications such as **frequency** synthesis, quadrature signal generation and phase locked loops (PLLs).

Files:

Contributors: Timmes, F. X, Townsend, Richard H. D., Bauer, Evan B., Thoul, Anne, Fields, C. E., Wolf, William M.

Date: 2019-03-10

MESA inlists associated with The Impact of White Dwarf Luminosity Profiles on **Oscillation** **Frequencies**
... MESA inlists associated with The Impact of White Dwarf Luminosity Profiles on **Oscillation** **Frequencies**

Files:

Contributors: Lubich, L.

Date: 2018-02-20

**Oscillators** are often followed by square wave forming circuits and **frequency** dividers. Traditionally, the level of the phase noise, transferred from the **oscillator** outputs to the square waves obtained is calculated ignoring the correlations in the **oscillator** phase noise spectrum. In this paper, accurate expressions are derived, taking into account the phase noise mechanisms in the **oscillators**. The phase noise power spectral densities are calculated in both the traditional way and by using the proposed expressions and they are compared. The situations where the proposed expressions can be useful are identified....**oscillator**...**frequency** divider ... **Oscillators** are often followed by square wave forming circuits and **frequency** dividers. Traditionally, the level of the phase noise, transferred from the **oscillator** outputs to the square waves obtained is calculated ignoring the correlations in the **oscillator** phase noise spectrum. In this paper, accurate expressions are derived, taking into account the phase noise mechanisms in the **oscillators**. The phase noise power spectral densities are calculated in both the traditional way and by using the proposed expressions and they are compared. The situations where the proposed expressions can be useful are identified.

Files: