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- Diagrammatic sketch of a
**qubit**coupled with structured environments. The environment in the 1st case consists of a two level system coupled to a bath. The environment in 2nd case is a damped harmonic**oscillator**. ... (1st case) P(t) as a function of time for the on-resonance case (ΔA=ΔB), where the decoherence is enhanced with T. Inset (a): Fourier analysis of P(t). One can see that two**frequencies**are dominating the dynamics and the peaks locate at ΔA±g0. Inset (b): The effective spectral density Jeff(ω). Here, it is not πJeff(ΔA) but πJeff(ΔA±g0) indicates the damping rate γA. ... (2nd case) P(t) as a function of time, where the decoherence is enhanced with T. Inset (a): Fourier analysis of the main plot. One sees that two**frequencies**are dominating the dynamics and the splitting of the peaks increases with temperature. Inset (b): The effective spectral density Jeff(ω). The square, triangle and circle points correspond to the dominant**frequencies**of P(t) in different temperatures, respectively. One can see that smaller Jeff’s, which characterize long time dynamics, are almost the same for three different temperatures. This is the reason why the damping rate of P(t) is almost not changing with different temperatures.Data Types:- Image

- Comparison between simulated evolution of a
**qubit's**Rabi**oscillations**and processed measurement signal for p¯=0.5, Δp=0.1 and τ=TR/16. Dashed curve: |c1|2 over time (in units of the Rabi period TR) in the presence of weak measurements. Dotted curve: |c1|2 over time in the absence of measurements. The solid curve corresponds to the evolution of the estimate g based on the measurement results. ... Power spectrum of |c1|2 in the presence of measurements. It assumes its maximum at the**frequency**ΩR of the undisturbed Rabi**oscillations**.Data Types:- Image

- The Allan deviation of fractional temperature fluctuations of a liquid nitrogen bath (curve 1) and a solid nitrogen bath (curve 2) measured with the ac-bridge. Curve 3 are the measured room temperature fractional fluctuations. Curve 4 are the measured fractional temperature fluctuations in the cavity determined by measuring the
**oscillator****frequency**fluctuations cooled by a liquid nitrogen bath (77 K). Curve 5 are the measured fractional temperature fluctuations in the cavity determined by measuring the**oscillator****frequency**fluctuations cooled to 58 K by a solid nitrogen bath and a foil heater and temperature controller. Curve 6 are the inferred fractional temperature fluctuations in the cavity passively cooled by a solid nitrogen bath (52 K). ...**Frequency**Standards and Metrology Research Group, Department of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia... Schematic of loop**oscillator**used.Data Types:- Image

**Qubit**Data Types:- Image

- (Color online) |A|2 is the probability of finding the spin system in the state |⇓↓〉. It
**oscillates**at the high**frequency**D (=2.88GHz). The**frequency**of the beats is χ/2 (=16.7MHz). The amplitude of**oscillations**is also modulated by an additional cosine wave signal of**frequency**χ (see text). |C|2 is the probability of finding the spin system in the state |0↓〉. It**oscillates**at the low**frequency**χ. It is almost zero in the time interval 90–100ns. The probability of finding spin system in the state |⇑↓〉, |B|2, has the same**oscillations**than |A|2 but it is anti-phase (see Fig. 3). ... Ideal truth table and schematic representation of a two-**qubit**CNOT gate irradiated by a sequence of two microwave π/2-pulses of equal width t and a variable waiting time between pulses τ. In the text, x and y are the states of two impurity spins of diamond, namely the spin-12 carried by the P1 center and the spin-1 carried by the NV−1 color center. The symbol ⊕ is the addition modulo 2, or equivalently the XOR operation. ... (Color online) NV−1 Rabi**oscillations**. Control**qubit**down: blue, red and green lines correspond, respectively, to the time evolution of |A|2, |B|2 and |C|2, i.e., the probabilities of finding the spin system in the state |⇓↓〉, |⇑↓〉 and |0↓〉. Control**qubit**up: red, blue and green lines represent, respectively, |A′|2, |B′|2 and |C′|2, i.e., the probabilities of finding the spin system in the state |⇓↑〉, |⇑↑〉 and |0↑〉, i.e., |A′|2=|B|2, |B′|2=|A|2 and |C′|2=|C|2 (see text). Fig. 4 gives details in the interval 60–120ns. They can also be revealed by a zoom in.Data Types:- Image
- Tabular Data

- High
**Frequency**& Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, JapanData Types:- Image

- FEMTO-ST Institute,
**Frequency**and Time Department, 26, Chemin de l’Epitaphe, Besançon 25000, France... Measured phase noise of a 5MHz high quality quartz crystal resonator. fL denotes the so-called Leeson**frequency**, i.e. a half of a resonator bandwidth. The dashed line is needed to identify the PSD value at f=1Hz from the carrier which is used to calculate the corresponding Allan deviation [2].Data Types:- Image

- (Color online.) Schematic diagram of the displaced
**oscillator**basis. The horizontal axis x′=x2mω0ℏ. All three wells maintain the same harmonic character, and usual eigenstates as well. The equilibrium position of the left (or the right) well is shifted by a specific constant. The shift direction is to the left (or right) when the**qubits**are in |+〉=|e1,e2〉 (or |−〉=|g1,g2〉). The middle potential well which is double degenerate corresponds to non-displaced case in which the states of the two**qubits**are opposite, i.e., |0〉 (|g1,e2〉 or |e1,g2〉), and the equilibrium position is higher than the others. The eigenstates which have the same value of n in the left well are degenerate with that in the right well. ... (Color online.) (a) Schematic diagram of the structure. The two light blue squares are improved three-junction flux**qubits**fabricated to the center conductor. (b) Schematic graph of the system. Two identical**qubits**(i.e. parameters Δ, ϵ, energy-level splitting Eq and coupling strength g for both**qubits**are of the same value) viewed as a two-level system with ground state |g〉 and excited state |e〉, are coupled to a harmonic**oscillator**whose characteristic**frequency**is ω0. ... (Color online.) Comparison between the displaced**oscillator**adiabatic approximation method and the numerical solution for the lowest two levels. ℏω0/Eq=10. The black solid lines stand for the lowest two energy levels calculated by adiabatic approximation. The green dashed line and the red dashed line correspond to the lowest two energy levels obtained by the numerical solution. (a) θ=0. (b) θ=π/6. (c) θ=π/4. (d) θ=π/3.Data Types:- Image

- Flux
**qubit**... Example of the dynamics for the symmetric case ε=0, where the**oscillator****frequency**is in resonance with the TSS**frequency**, i.e., Ω=Δ0. Parameters are: g=0.18Δ0, κ=0.014 (→α=0.004), kBT=0.1ℏΔ0. QUAPI parameters are M=12, K=1, Δt=0.06/Δ0. ... Sz(ω) for two values of the**oscillator****frequency**Ω. Parameters are: ε=0, g=0.07Δ0, κ=0.014, kBT=0.1ℏΔ0. ... Main: Dephasing rates corresponding to peak 1 and peak 2 in the Figs. 1 and 3 as a function of the HO**frequency**Ω. The parameters are: ε=0, g=0.07Δ0, κ=0.014, kBT=0.1ℏΔ0. Inset: Same for stronger damping κ=0.02 with α=0.01=const. (like in [15]). This implies that with varying Ω also g is changed.Data Types:- Image

- The sketch of the
**qubit**–detector systems considered in the paper. The**qubit**(two coupled quantum dots: x and y) is coupled electrostatically via U parameter with one of the detector QDs. Panels A, B and C correspond to the single-QD, double-QD and triple-QD detectors, respectively. ...**Qubit**QD occupations, nx(t), versus time for the DQD (TQD) detector – curves a–c (d, e) and for different initial conditions. Curves a and d:**qubit**is ‘frozen’ in the state nx=0,ny=1 until t=40 when the occupancies of all detector QDs achieve their steady state values. Curves b and e:**qubit**is ‘frozen’ in the state nx=0,ny=1 and also n2=n3=0 until t=40 when the occupancy of the first detector QD, n1, achieves its steady state value. Curve c: all couplings in the**qubit**–detector system are switched on at t=40 (i.e. nx=0,ny=1, n1=n2=0 for t<40). The other parameters: Vxy=4, U=4, Vij=0.5, Γ=1, εi=0 and μL=−μR=20. ... Charge**qubit**... The nearby**qubit**QD occupation, nx(t), as a function of time for the triple-QDs detector shown in Fig. 1C for different values of the**qubit**tunneling amplitude Vxy=1,2 and 4, respectively. The upper (bottom) panel corresponds to μL=−μR=1 (μL=−μR=10). The other parameters are εi=0, V12=V23=1, Vxy=4, U=4 and the initial conditions as in Fig. 2. ... Nearby**qubit**QD occupation, nx(t), as a function of time for the triple-QD detector (see Fig. 1C) for different values of U parameter: U=0,2,3,4 and 6, respectively. The bias voltage μL=−μR=10, other parameters and initial conditions as in Fig. 6. ... Nearby**qubit**QD occupation, nx(t), as a function of time for different forms of the detector depicted in Fig. 1. The upper (bottom) panel corresponds to the ΓL=ΓR=Γ=1 (Γ=0.2). The tunneling coupling between QDs is V=1 for the detector and Vxy=4 for the**qubit**, energy levels of all QDs are equal to εi=0, μL=−μR=10 and U=4. The**qubit**was ‘frozen’ in the configuration nx=0, ny=1 for t<15, i.e. until the detector QD occupancies and currents jL and j12 achieved their stationary values. The curves B and C are shifted down by 1 and 2 for clarity. ...**Qubit**dynamicsData Types:- Image

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