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  • Current-composed quantity Q(t) (solid lines) and the far-removed qubit QD occupancy, n3 (dashed lines), as a function of time for the horizontal qubit-detector connection, U13=U24=0, 2 or 4, respectively. μL=−μR=20, ΓL=5, ΓR=10, U12=U34=5 and the other parameters are the same as in Fig. 2. The lines for U13=U24=2 (4) are shifted by −1 (−2) for better visualisation. ... The sketch of the qubit-detector systems discussed in the text. Double quantum dot (1 and 4) between the left and right electron reservoirs stands for the qubit charge detector. Qubit is represented by two coupled quantum dots (2 and 3) occupied by a single electron. Straight black (zig-zag red) lines correspond to the tunnel matrix elements V14, V23 (Coulomb interactions, e.g. U14, U24) between the appropriate states. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this article.) ... The asymptotic pulse-induced current I(τ) against the time interval (pulse length) τ – for details see the text – and the charge occupation of the far-removed qubit QD, n3, (dashed lines) for the qubit-detector system schematically shown in Fig. 1b. The upper (bottom) panel corresponds to ΓL=5, ΓR=10 (ΓL=5, ΓR=1). μL=−μR=20 and the other parameters are the same as in Fig. 2. The current lines are multiplied by −2 for better visualisation. ... Current-composed quantity Q(t) (solid lines) and the charge occupation of the far-removed qubit QD, n3, (dashed lines) as a function of time for the qubit-detector system schematically shown in Fig. 1b. The upper (bottom) panel corresponds to (ΓL,ΓR)=(5,1) ((ΓL,ΓR)=(5,10)). The other parameters are: μL=−μR=2 or μL=−μR=20, ε1,2,3,4=0, U24=5, U14=50, n2(t<10)=0, n3(t<10)=1. The lines for μL=−μR=20 are shifted by −1 for better visualisation. ... Upper panel: Current-composed quantity Q(t) (solid lines) and the far-removed qubit QD occupancy, n3, (dashed lines) as a function of time for different qubit-detector connections shown in Fig. 1d (U12=5), Fig. 1c (U12=U24=5) and Fig. 1b (U24=5)—the upper, middle and lower curves, respectively. The bottom panel depicts the corresponding left (solid lines) and right (dashed lines) currents, IL(t), IR(t), flowing in the system for the above three qubit-wire connections. μL=−μR=2, ΓL=5, ΓR=10 and the other parameters are the same as in Fig. 2. The lines in the upper panel for U12=U24=5 and for U24=5 are shifted by −1 and −2, respectively, and by −0.15 and −0.3 in the bottom panel. Note different scales in the vertical axis of both panels.
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  • Diagrammatic representation of time-resolved CARS. Both time-circuit and Feynman diagram are illustrated for a non- overlapping sequence of P, S, P′ pulses, with central frequency of the S-pulse chosen to be outside the absorption spectrum of the B←X transition, to ensure that only the P(0,3) component of the third-order polarization is interrogated. In this dominant contribution, all three pulses act on bra (ket) state while the ket (bra) state evolves field free. Note, for the Feynman diagrams, we use the convention of Ref. [6], which is different than that of Ref. [5]. ... The wavepacket picture associated with the evolution of the ket-state in the diagram of Fig. 1, for resonant CARS in iodine. The required energy matching condition for the AS radiation, Eq. (10b) of text, can only be met when the packet reaches the inner turning point of the B-surface. Once prepared, ϕ(3)(t) will oscillate, radiating periodically every time it reaches the inner turning point.
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  • Schematic diagram of a cryogenic crystal oscillator based on a SiGe HBT. ... Oscillator model for the phase noise analysis. ... Oscillator mounting inside the cryocooler. ... Time and Frequency Department, FEMTO-ST Institute, Besançon, France... Schematic diagram of a cryogenic crystal oscillator based on a MOSFET transistor. ... Low noise oscillators... PSD of two HBT-based liquid helium oscillators, for different bias voltages.
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  • Qubit dynamics in Bloch ball picture. North pole corresponds to the excited (antisymmetric) energy eigenstate |1〉 and south pole corresponds to the ground (symmetric) state |0〉. Initially the electron is localized in one of the dots. Quality of Rabi oscillations Q=40. The effect of image charge potential: (a) K=0 and (b) K=0.4. ... Quality of qubit Rabi oscillations vs. distance to a metal surface. Centers of quantum dots are located 100nm apart. Lines and points correspond to analytical and numerical solutions, respectively. ... Quality of qubit Rabi oscillations vs. the distance between quantum dots. Qubit is located 50nm far from the metal surface. Lines and points correspond to analytical and numerical solutions, respectively. ... The moving charge in the qubit drags charges in metal that indispensably entails Joule loss: d is a double dot separation and D is a distance to the metal surface.
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  • Illustration of a linear ion trap including an axial magnetic field gradient. The static field makes individual ions distinguishable in frequency space by Zeeman-shifting their internal energy levels (solid horizontal lines represent qubit states). In addition, it mediates the coupling between internal and external degrees of freedom when a driving field is applied (dashed horizontal lines stand for vibrational energy levels of the ion string, see text). ... Rabi oscillations on the optical E2 transition S1/2-D5/2 in Ba + . A fit of the data (solid line) yields a Rabi frequency of 71.4 × 2πkHz and a transversal relaxation time of 100 μs (determined by the coherence time of the ir light used to drive the E2 resonance). ... Illustration of the coupled system ‘qubit ⊗ harmonic oscillator’ in a trap with magnetic field gradient. Internal qubit transitions lead to a displacement dz of the ion from its initial equilibrium position and consequently to the excitation of vibrational motion. In the formal description the usual Lamb–Dicke parameter is replaced by a new effective one (see text). ... (a) Relevant energy levels and transitions in 138Ba + . (b) Schematic drawing of major experimental elements. OPO: Optical parametric oscillator; YAG: Nd:YAG laser; LD: laser diode; DSP: Digital signal processing system allows for real time control of experimental parameters; AOM: Acousto-optic modulators used as optical switches and for tuning of laser light; PM: Photo multiplier tube, serves for detection of resonance fluorescence. All lasers are frequency and intensity stabilized (not shown). ... Schematic drawing of the resonances of qubits j and j + 1 with some accompanying sideband resonances. The angular frequency vN corresponds to the Nth axial vibrational mode, and the frequency separation between carrier resonances is denoted by δω.
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  • The same as in Fig. 4 for U=2 and for the time-dependent energy levels ε1 and ε2 presented in the inset in the left panel—they oscillate harmonically with frequency ω=1 and the pulse envelope has a Gaussian shape of duration τ=30 centered at t0=100. ... The same as in Fig. 3 but for U=0 (upper panels) and for U=2 (lower panels) for the time-dependent energy levels ε1 and ε2 presented in the inset, in the upper left panel—they oscillate harmonically around the values ε=±1 with frequency ω=0.1, and the pulse envelope has a Gaussian shape of duration τ=30 centered at t0=92. The energy levels of the right qubit have constant values ε3=ε4=1. ... Coupled qubits... Occupancy probability n1(t=∞) of the first QD of the left qubit (qubits are in the perpendicular configuration) as a function of the frequency ω of the time-dependent V1(t) displayed in the inset—it oscillates harmonically with ω=0.5 and the pulse envelope has a Gaussian shape of duration τ=30, V2=1, U1=U2=2, εi=0, n1(0)=n3(0)=1. ... Occupation probability n1(t) of the first QD in the left qubit (the left panel) and n4(t) of the second QD in the right qubit (the right, panel) as the functions of time for U=10. The energy levels ε1 and ε2 of the left qubit oscillate harmonically around the values ε=±2 with amplitude Δ=2, frequency ω=0.05 (in V/ℏ units, see the inset in the left panel) and energy levels of the right qubit having constant values, ε3=−ε4=2. The qubits are in the linear configuration. ... Schematic representation of two interacting qubits formed by two DQDs with one excess electron in each qubit. The broken lines correspond to the Coulomb interaction U between the electrons localized on the neighboring QDs of both qubits and V denotes the interdot tunneling matrix element. ... Charge oscillations
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  • Optoelectronics and High Frequency Device Research Laboratories, 34 Miyukigaoka, Tsukuba, Ibaraki 305, Japan... High-frequency characteristics of the p-ch HJFET
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  • Average PTO power as a function of oscillating frequency for straight (♦: solid line) and bent leg (□: broken line) tines (oscillation angle β=+27°). ... Subsoiler draft signals with time for the control and the range of oscillating frequencies. ... Dominant frequency of draft signal over the oscillating frequency range. ... Proportion of cycle time for cutting and compaction phases versus oscillating frequency (oscillation angle β=+27°). ... Dominant frequency of torque signal over the oscillating frequency range. ... Frequency... Oscillating tine
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  • Qubits in solids... Schematic diagram of qubits addressed in a frequency domain. The ions whose 3H4(1)± 3 2–1D2(1) transitions are resonant with a common cavity mode are employed as qubits. ... Basic scheme of the concept of the frequency-domain quantum computer. The atoms are coupled to a single cavity mode. Lasers with frequencies of νk and νl are directed onto the set of atoms and interact with the kth and lth atoms selectively.
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  • Traveling wave resonator with two ports incorporated into interferometric frequency discriminator for oscillator stabilisation. ... Modified Galani oscillator stabilisation technique utilising travelling wave resonator with standing wave ratio. ... Frequency Standards and Metrology Group, School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley 6009, Australia
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