### 21982 results for qubit oscillator frequency

Contributors: Erik Smedler, Per Uhlén

Date: 2014-03-01

**Frequency** modulation...Calcium (Ca2+) **oscillations** are ubiquitous signals present in all cells that provide efficient means to transmit intracellular biological information. Either spontaneously or upon receptor ligand binding, the otherwise stable cytosolic Ca2+ concentration starts to **oscillate**. The resulting specific oscillatory pattern is interpreted by intracellular downstream effectors that subsequently activate different cellular processes. This signal transduction can occur through **frequency** modulation (FM) or amplitude modulation (AM), much similar to a radio signal. The decoding of the oscillatory signal is typically performed by enzymes with multiple Ca2+ binding residues that diversely can regulate its total phosphorylation, thereby activating cellular program. To date, NFAT, NF-κB, CaMKII, MAPK and calpain have been reported to have **frequency** decoding properties....**Frequency** modulated Ca2+ **oscillations**. (A) A computer generated (in silico) **oscillating** wave with the parameters: period (T), **frequency** (f), full duration half maximum (FDHM), and duty cycle is depicted. (B) **Oscillating** wave **frequency** modulated by agonist concentration. (C) **Oscillating** wave **frequency** modulated by the different agonists X, Y, and Z. Three single cell Ca2+ recordings of a Fluo-4/AM-loaded neuroblastoma cell (D), HeLa cell (E), and cardiac cell (F) with the parameters T, f, FDHM, and duty cycle stated. Scale bars are 100s.
...**Frequency** decoders and host cells. Illustration showing the **frequencies** and periods that modulate the different **frequency** decoders and host cells.
...**Frequency** decoding ... Calcium (Ca2+) **oscillations** are ubiquitous signals present in all cells that provide efficient means to transmit intracellular biological information. Either spontaneously or upon receptor ligand binding, the otherwise stable cytosolic Ca2+ concentration starts to **oscillate**. The resulting specific oscillatory pattern is interpreted by intracellular downstream effectors that subsequently activate different cellular processes. This signal transduction can occur through **frequency** modulation (FM) or amplitude modulation (AM), much similar to a radio signal. The decoding of the oscillatory signal is typically performed by enzymes with multiple Ca2+ binding residues that diversely can regulate its total phosphorylation, thereby activating cellular program. To date, NFAT, NF-κB, CaMKII, MAPK and calpain have been reported to have **frequency** decoding properties.

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Contributors: S Lee, R Blowes, A.D Milner

Date: 1998-09-01

Summary of resonance **frequencies** found in all 10 babies (1 and 2 represents first and second run, respectively)
...A screen from our phase analysis program, showing phase analysis performed at four points of the respiratory cycle: top of breath, mid-inspiration, mid-expiration and bottom of breath. Corresponding points from the driving trace and the mouth pressure trace are matched and the phase difference calculated. In this case, the phase difference at the top of breath is 0° at an **oscillating** **frequency** of 20 Hz.
...high-**frequency** **oscillation**...In an **oscillating** system driven by a sine wave pump, the resonance **frequency** of the respiratory system can be determined using phase analysis. At resonance **frequency**, when elastance and inertance cancel out, flow becomes in-phase with resistance. In premature infants with respiratory distress syndrome, owing to surfactant deficiency, localized areas of hyperinflation and collapse develop, resulting in complex changes in overall pulmonary mechanics. We investigated the effect of measuring resonance **frequency** of the respiratory system by phase analysis at different points of the respiratory cycle: end of inspiration, end of expiration, mid-inspiration and mid-expiration. Ten ventilated premature infants with respiratory distress syndrome were studied, gestational age ranged from 24 to 30 weeks (mean 27.6 weeks) and birth weight ranged from 0.7 to 1.505 kg (mean 0.984 kg). Results: The resonance **frequency** was consistently higher when measured at the end of inspiration compared with the end of expiration. The expected trend of phase variation, that is, negative below the resonance **frequency** and positive above, was most consistently found when analysis was done at the end of inspiration. Conclusions: These findings were most likely a result of the complexity of pulmonary mechanics in the surfactant-deficient lungs, rendering the single compartment model we based our theory on inadequate. However, phase analysis performed at the end of inspiration seemed to produce the most reliable and consistent results. ... In an **oscillating** system driven by a sine wave pump, the resonance **frequency** of the respiratory system can be determined using phase analysis. At resonance **frequency**, when elastance and inertance cancel out, flow becomes in-phase with resistance. In premature infants with respiratory distress syndrome, owing to surfactant deficiency, localized areas of hyperinflation and collapse develop, resulting in complex changes in overall pulmonary mechanics. We investigated the effect of measuring resonance **frequency** of the respiratory system by phase analysis at different points of the respiratory cycle: end of inspiration, end of expiration, mid-inspiration and mid-expiration. Ten ventilated premature infants with respiratory distress syndrome were studied, gestational age ranged from 24 to 30 weeks (mean 27.6 weeks) and birth weight ranged from 0.7 to 1.505 kg (mean 0.984 kg). Results: The resonance **frequency** was consistently higher when measured at the end of inspiration compared with the end of expiration. The expected trend of phase variation, that is, negative below the resonance **frequency** and positive above, was most consistently found when analysis was done at the end of inspiration. Conclusions: These findings were most likely a result of the complexity of pulmonary mechanics in the surfactant-deficient lungs, rendering the single compartment model we based our theory on inadequate. However, phase analysis performed at the end of inspiration seemed to produce the most reliable and consistent results.

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Contributors: Jing-Lin Xiao

Date: 2013-01-01

**Qubit**...We study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron strongly coupled to LO-phonon in a quantum rod (QR) with a hydrogen-like impurity at the center by using variational method of Pekar type. This QR system may be used as a two-level quantum **qubit**. When the electron is in the superposition state of the ground and the first excited states, we obtained the time evolution of the electron probability density **oscillating** in the QR with a certain period. We then investigate the effects of the temperature and the hydrogen-like impurity on the time evolution of the electron probability density and the **oscillation** period. It is found that the electron probability density and the **oscillation** period increase (decrease) with increasing temperature in lower (higher) temperature regime. The electron probability density and the **oscillation** period decrease (increase) with increasing electron–phonon coupling strength when the temperature is lower (higher). Whereas they increase (decrease) with increasing Coulomb bound potential when the temperature is lower (higher)....The **oscillation** period T0 changes with the temperature T and Coulomb bound potential β.
...The **oscillation** period T0 changes with the temperature T and electron phonon coupling strength α .
... We study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron strongly coupled to LO-phonon in a quantum rod (QR) with a hydrogen-like impurity at the center by using variational method of Pekar type. This QR system may be used as a two-level quantum **qubit**. When the electron is in the superposition state of the ground and the first excited states, we obtained the time evolution of the electron probability density **oscillating** in the QR with a certain period. We then investigate the effects of the temperature and the hydrogen-like impurity on the time evolution of the electron probability density and the **oscillation** period. It is found that the electron probability density and the **oscillation** period increase (decrease) with increasing temperature in lower (higher) temperature regime. The electron probability density and the **oscillation** period decrease (increase) with increasing electron–phonon coupling strength when the temperature is lower (higher). Whereas they increase (decrease) with increasing Coulomb bound potential when the temperature is lower (higher).

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Contributors: Mina Amiri, Jean-Marc Lina, Francesca Pizzo, Jean Gotman

Date: 2016-01-01

Examples of a spike without HFOs (left) and a spike with HFOs (right), as defined with the Analytic Morse wavelet in the time–**frequency** domain.
...High **Frequency** **Oscillations**...Parameter selection for the Analytic Morse Wavelet; top: time–**frequency** presentation for different values of n (m=40), bottom: raw signal and filtered signal (80–250Hz). Blue lines represent HFO interval marked visually.
...Examples of detection errors. Left: HFO without isolated blob but having **oscillation** in the raw signal. Right: HFO without visible **oscillation** in the raw signal but representing an isolated peak. Blue lines show the HFO interval marked by reviewers.
...Time–**frequency**...To demonstrate and quantify the occurrence of false High **Frequency** **Oscillations** (HFOs) generated by the filtering of sharp events. To distinguish real HFOs from spurious ones using analysis of the raw signal. ... To demonstrate and quantify the occurrence of false High **Frequency** **Oscillations** (HFOs) generated by the filtering of sharp events. To distinguish real HFOs from spurious ones using analysis of the raw signal.

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Contributors: Dong-Qi Liu, Gang-Qin Liu, Yan-Chun Chang, Xin-Yu Pan

Date: 2014-01-01

Detection and manipulation of the **qubit**. (a) Fluorescence image of nanodiamond prepared on the CPW transmission line. NV S1 is circled. The inset is a photo of CPW with 20μm gaps fabricated on a silica glass. (b) CW ODMR spectrum for NV S1. The inset is energy levels of NV center. A 532nm laser is used to excite and initialize the NV center. Fluorescence is collected by a confocal microscope. (c) Rabi **oscillation** of NV S1. Rabi **oscillation** period is about 62ns. (d) Hahn echo and CPMG control pulse sequences. πx (πy) implies the direction of microwave magnetic fields parallel to x (y).
...Spectral density of the spin bath. (a) NV S1, (b) NV S2. All values of spectral density S(ω) of the spin bath are extracted from the CPMG data (blue points). Each blue data point represents a specific probed **frequency** ω=πn/t, in which n is the number of control pulses and t is the specific duration. The red points are the average values at a certain **frequency**. The mean spectral density is fit to the Lorentzian function (Eq. (3)) (green line). (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this article.)
...Overcoming the spin **qubit** decoherence is a challenge for quantum science and technology. We investigate the decoherence process in nanodiamonds by Carr–Purcell–Meiboom–Gill (CPMG) technique at room temperature. We find that the coherence time T2 scales as nγ. The elongation effect of coherence time can be represented by a constant power of the number of pulses n. Considering the filter function of CPMG decoupling sequence as a δfunction, the spectrum density of noise has been reconstructed directly from the coherence time measurements and a Lorentzian noise power spectrum model agrees well with the experiment. These results are helpful for the application of nanodiamonds to nanoscale magnetic imaging....Characterization of lifetime of NV center spins. (a) Ramsey interference of NV S1 (circle) and NV S2 (diamond). The **oscillation** in Ramsey signal originates from the beating among different transitions corresponding to the host three 14N nuclear spin states. The **oscillation** **frequency** of Ramsey signal is equal to microwave detuning from spin resonance. Solid lines ~exp[−(t/T2⁎)m] fit the experimental data points, where m is a free parameter. (b) Comparison of Hahn echo coherence time T2 of NV S1 (circle) and NV S2 (diamond). The solid lines are fits to ~exp[−(t/T2)p], in which p is a fit parameter.
... Overcoming the spin **qubit** decoherence is a challenge for quantum science and technology. We investigate the decoherence process in nanodiamonds by Carr–Purcell–Meiboom–Gill (CPMG) technique at room temperature. We find that the coherence time T2 scales as nγ. The elongation effect of coherence time can be represented by a constant power of the number of pulses n. Considering the filter function of CPMG decoupling sequence as a δfunction, the spectrum density of noise has been reconstructed directly from the coherence time measurements and a Lorentzian noise power spectrum model agrees well with the experiment. These results are helpful for the application of nanodiamonds to nanoscale magnetic imaging.

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Contributors: Michael G. Tanner, David G. Hasko, David A. Williams

Date: 2006-04-01

Resonance response of the SET current to applied microwave **frequencies**, (a) over a large **frequency** range due to coupling with all device elements. (b) A resonance of interest believed to be associated with the IDQD. Central resonance peak is periodically split or suppressed with varying gate potential Vg2. The inset figure shows the response at Vg2=−9.5V (dashed line) and at Vg2=−8V plotted without offset for comparison. The feature repeats periodically as gate potential is increased further.
...**Qubit**...Differentiated SET current measured at 4.2K and zero source–drain bias as Vg1 is swept and Vg2 is incremented. Inset shows the main features: one main Coulomb **oscillation** indicated by the dashed line and subsidiary **oscillations** shown by the dotted lines.
... The fabrication methods and low-temperature electron transport measurements are presented for circuits consisting of a single-island single-electron transistor coupled to an isolated double quantum-dot. Capacitively coupled ‘trench isolated’ circuit elements are fabricated in highly doped silicon-on-insulator using electron beam lithography and reactive ion etching. Polarisation of the isolated double quantum-dot is observed as a function of the side gate potentials through changes in the conductance characteristics of the single-electron transistor. Microwave signals are coupled into the device for excitation of the polarisation states of the isolated double quantum-dot. Resonances attributed to an energy level splitting of the polarisation states are observed with an energy separation appropriate for quantum computation.

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Contributors: Wei Xiao, Jing-Lin Xiao

Date: 2012-10-01

The period of **oscillation** T0 in a QR as a function of the transverse and longitudinal effective confinement lengths of the QR lp and lv.
...We study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron, which is strongly coupled to LO-phonon in a quantum rod with a hydrogen-like impurity at the center by using the variational method of Pekar type. This quantum rod system may be used as a two-level quantum **qubit**. When the electron is in the superposition state of the ground and the first-excited states, the probability density of the electron **oscillates** in the quantum rod. It is found that the probability density and the **oscillation** period are individually increased and decreased due to the presence of the Coulomb interaction between the electron and the hydrogen-like impurity. The **oscillation** period is an increasing function of the ellipsoid aspect ratio and the effective confinement lengths of the quantum rod, whereas it is a decreasing one of the electron–phonon coupling strength....The period of **oscillation** T0 in a QR as a function of the electron–phonon coupling strength α and the Coulomb bound potential β.
...**Qubit**...The period of **oscillation** T0 in a QR as a function of the ellipsoid aspect ratio e′ and the electron–phonon coupling strength α.
... We study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron, which is strongly coupled to LO-phonon in a quantum rod with a hydrogen-like impurity at the center by using the variational method of Pekar type. This quantum rod system may be used as a two-level quantum **qubit**. When the electron is in the superposition state of the ground and the first-excited states, the probability density of the electron **oscillates** in the quantum rod. It is found that the probability density and the **oscillation** period are individually increased and decreased due to the presence of the Coulomb interaction between the electron and the hydrogen-like impurity. The **oscillation** period is an increasing function of the ellipsoid aspect ratio and the effective confinement lengths of the quantum rod, whereas it is a decreasing one of the electron–phonon coupling strength.

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Contributors: Rina Zelmann, Maeike Zijlmans, Julia Jacobs, Claude-E. Châtillon, Jean Gotman

Date: 2009-08-01

High **Frequency** **Oscillations**...High **Frequency** **Oscillations** (HFOs), including Ripples (80–250Hz) and Fast Ripples (250–500Hz), can be recorded from intracranial macroelectrodes in patients with intractable epilepsy. We implemented a procedure to establish the duration for which a stable measurement of rate of HFOs is achieved. ... High **Frequency** **Oscillations** (HFOs), including Ripples (80–250Hz) and Fast Ripples (250–500Hz), can be recorded from intracranial macroelectrodes in patients with intractable epilepsy. We implemented a procedure to establish the duration for which a stable measurement of rate of HFOs is achieved.

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Contributors: Alberto Pretel, John H. Reina, William R. Aguirre-Contreras

Date: 2008-03-01

In all plots the decay rates κ/g=0.1, γr/g=4.35×10-2, and cavity factor Q=1400. The quantum dot excitonic Bohr **frequency** is assumed to be in resonance with the cavity field **frequency**, i.e., ωqd=ωc. The amplitude of the external laser field to the cavity decay rate ratio is fixed to I/κ=631. The coherence ρ01≡ρ(0,1) dynamics is plotted for: (a) Δωcl=0.4g; (b) Δωcl=g; (c) Δωcl=100g; (d) Δωcl=1000g. The cavity photons mean number is plotted in (e) and (f). We have used a logarithmic scale for the time axis and the values: (i) Δωcl=g; (ii) Δωcl=1000g, for the solid and dotted curves, respectively.
...Rabi **oscillations**...Within the density matrix formalism, we report on the quantum control of the excitonic coherences in quantum dots coupled to a single mode field resonant semiconductor cavity. We use an external classical laser field to drive the dynamical response of the excitonic states. Dissipation mechanisms associated with the cavity field and the excitonic states are explicitly included in the model. Our numerical simulations of the excitonic dynamics are in good agreement with recent experimental reports. Furthermore, we compute and show how to tailor such a dynamics in the presence of the laser field by means of controlling the detuning between the laser and the cavity field **frequencies**. The results are analyzed with a view to implementing quantum control of local **qubit** operations. ... Within the density matrix formalism, we report on the quantum control of the excitonic coherences in quantum dots coupled to a single mode field resonant semiconductor cavity. We use an external classical laser field to drive the dynamical response of the excitonic states. Dissipation mechanisms associated with the cavity field and the excitonic states are explicitly included in the model. Our numerical simulations of the excitonic dynamics are in good agreement with recent experimental reports. Furthermore, we compute and show how to tailor such a dynamics in the presence of the laser field by means of controlling the detuning between the laser and the cavity field **frequencies**. The results are analyzed with a view to implementing quantum control of local **qubit** operations.

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Contributors: Tadashi Watanabe

Date: 2008-01-21

Variation of **frequency** shift due to the amplitude and the rotation rate.
...Conditions for zero **frequency** shift and zero pressure difference. Broken lines indicate linear fitting lines through the origin.
...Free-decay **oscillations** and rotations of a levitated liquid droplet are simulated numerically, and the **frequency** shift of drop-shape **oscillations** is studied. It is shown for an **oscillating**-rotating liquid droplet that the **oscillation** **frequency** decreases as the amplitude of drop-shape **oscillations** increases, while it increases as the rotation rate increases. The pressure difference between the equator and the pole of the droplet is found to correspond to the **frequency** shift. It is also found that the relation between the amplitude and the rotation rate is linear both for zero **frequency** shift and for zero pressure difference....**Oscillation**...**Frequency** shift ... Free-decay **oscillations** and rotations of a levitated liquid droplet are simulated numerically, and the **frequency** shift of drop-shape **oscillations** is studied. It is shown for an **oscillating**-rotating liquid droplet that the **oscillation** **frequency** decreases as the amplitude of drop-shape **oscillations** increases, while it increases as the rotation rate increases. The pressure difference between the equator and the pole of the droplet is found to correspond to the **frequency** shift. It is also found that the relation between the amplitude and the rotation rate is linear both for zero **frequency** shift and for zero pressure difference.

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