### 461 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.

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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

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Contributors: White, William C.

Date: 1916-10-01

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Contributors: Sadegh Biabanifard, S. Mehdi Hosseini Largani, Shahrouz Asadi

Date: 2015-06-26

**frequency** stability...CMOS, x **frequency** stability, delay time...A combined skewed ring **oscillator** by different type of delay stages is presented. This paper aims to drive a high stable and relatively high **frequency** but still use a full transistor circuit for ring **oscillator** with combined delay stages and skewed connections. First we propose two types of common inverters then calculate their delay time and analysis their dependence of delay time to variation of power supply voltage. The simulation results verify that delay time of these two CMOS inverters show opposite behaviour versus power supply changing. So a combined structure can obtain more appropriate **frequency** stability versus power supply noise. Also in order to increase oscillation **frequency** we have used the negative skewed delay connections. The simulation results using HSPICE for 0.18 µm CMOS shows a good agreement with analysis results. In addition in this paper the mathematical justification for improved functioning of this combined skewed ring **oscillator** has been proved. This justification shows appropriate agreement with the simulation results. From mathematical point of view the proposed ring **oscillator** has better **frequency** stability in comparison with other types of ring **oscillators**. In fact, the oscillation **frequency** sensitivity to supply voltage noise is reduced considerably....ring **oscillator**...A combined skewed ring **oscillator** by different type of delay stages is presented. This paper aims to drive a high stable and relatively high **frequency** but still use a full transistor circuit for ring **oscillator** with combined delay stages and skewed connections. First we propose two types of common inverters then calculate their delay time and analysis their dependence of delay time to variation of power supply voltage. The simulation results verify that delay time of these two CMOS inverters show opposite behaviour versus power supply changing. So a combined structure can obtain more appropriate **frequency** stability versus power supply noise. Also in order to increase **oscillation** **frequency** we have used the negative skewed delay connections. The simulation results using HSPICE for 0.18 µm CMOS shows a good agreement with analysis results. In addition in this paper the mathematical justification for improved functioning of this combined skewed ring **oscillator** has been proved. This justification shows appropriate agreement with the simulation results. From mathematical point of view the proposed ring **oscillator** has better **frequency** stability in comparison with other types of ring **oscillators**. In fact, the **oscillation** **frequency** sensitivity to supply voltage noise is reduced considerably....COMBINED SKEWED CMOS RING **OSCILLATOR** ... A combined skewed ring **oscillator** by different type of delay stages is presented. This paper aims to drive a high stable and relatively high **frequency** but still use a full transistor circuit for ring **oscillator** with combined delay stages and skewed connections. First we propose two types of common inverters then calculate their delay time and analysis their dependence of delay time to variation of power supply voltage. The simulation results verify that delay time of these two CMOS inverters show opposite behaviour versus power supply changing. So a combined structure can obtain more appropriate **frequency** stability versus power supply noise. Also in order to increase **oscillation** **frequency** we have used the negative skewed delay connections. The simulation results using HSPICE for 0.18 µm CMOS shows a good agreement with analysis results. In addition in this paper the mathematical justification for improved functioning of this combined skewed ring **oscillator** has been proved. This justification shows appropriate agreement with the simulation results. From mathematical point of view the proposed ring **oscillator** has better **frequency** stability in comparison with other types of ring **oscillators**. In fact, the **oscillation** **frequency** sensitivity to supply voltage noise is reduced considerably.

Contributors: Omar Farouk Djibril , Gerard L. Gbaguidi Aisse, Gbaguidi S. Victor and Antoine Cokou Vianou.

Date: 2019-04-05

Portico **Frequency** of free **oscillations** Resonance Stiffness matrix method....In the modern world, high-rise buildings are in vogue, each year more and more large buildings built. One of the most common schemes for high-rise buildings is portico system, formed by combination of vertical (columns) and horizontal (beams) supporting members. However, as building grows in height, it must have enough strength and stiffness to withstand lateral loads imposed by wind or moderate earthquakes. Over last ten decades, there was therefore significant renewed interest in structures stability problem subjected to time-dependent loads. Considering dynamic problems in civil engineering field is necessary to ensure structure reliability in many applications. But dynamics problems study is often complex for inertia forces come from structure displacements which in turn depend on structures free **oscillations** **frequency**. The coincidence of this **frequency** of free **oscillation** with that of the forced **oscillations** caused by the wind involves the phenomenon of resonance which is very dangerous for the structures. It is therefore necessary to know how to determine the **frequency** of the free **oscillations** of the systems which constitutes the starting point for a dynamic study. To do this, the stiffness matrix method was used to determine the free **oscillation** **frequencies** of the multi-storey portico structures. It has been observed, therefore, that the **frequencies** of free **oscillations** don?t depend on time, neither on the amplitude of the **oscillations**, nor on the phase angle, but rather on the rigidity and the mass of the structures. ... In the modern world, high-rise buildings are in vogue, each year more and more large buildings built. One of the most common schemes for high-rise buildings is portico system, formed by combination of vertical (columns) and horizontal (beams) supporting members. However, as building grows in height, it must have enough strength and stiffness to withstand lateral loads imposed by wind or moderate earthquakes. Over last ten decades, there was therefore significant renewed interest in structures stability problem subjected to time-dependent loads. Considering dynamic problems in civil engineering field is necessary to ensure structure reliability in many applications. But dynamics problems study is often complex for inertia forces come from structure displacements which in turn depend on structures free **oscillations** **frequency**. The coincidence of this **frequency** of free **oscillation** with that of the forced **oscillations** caused by the wind involves the phenomenon of resonance which is very dangerous for the structures. It is therefore necessary to know how to determine the **frequency** of the free **oscillations** of the systems which constitutes the starting point for a dynamic study. To do this, the stiffness matrix method was used to determine the free **oscillation** **frequencies** of the multi-storey portico structures. It has been observed, therefore, that the **frequencies** of free **oscillations** don?t depend on time, neither on the amplitude of the **oscillations**, nor on the phase angle, but rather on the rigidity and the mass of the structures.

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).

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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**

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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.

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Contributors: Qasem M. Al-Mdallal

Date: 2012-04-25

Lock-on; streamwise **oscillation**; transverse
**oscillation**; fluid forces...This paper presents results obtained from the
numerical solution for the flow past an **oscillating** circular cylinder at
Reynolds number of 200. The **frequency** of **oscillation** was fixed to
the vortex shedding **frequency** from a fixed cylinder, f0, while the
amplitudes of **oscillations** were varied from to 1.1a, where a
represents the radius of the cylinder. The response of the flow
through the fluid forces acting on the surface of the cylinder are
investigated. The lock-on phenomenon is captured at low **oscillation**
amplitudes. ... This paper presents results obtained from the
numerical solution for the flow past an **oscillating** circular cylinder at
Reynolds number of 200. The **frequency** of **oscillation** was fixed to
the vortex shedding **frequency** from a fixed cylinder, f0, while the
amplitudes of **oscillations** were varied from to 1.1a, where a
represents the radius of the cylinder. The response of the flow
through the fluid forces acting on the surface of the cylinder are
investigated. The lock-on phenomenon is captured at low **oscillation**
amplitudes.