Phase gate

Fig. 11. Cutaway view of a CCD shift register where the ( ) represent gate electrodes. Voltage pulses appHed to the phase gates move photogenerated charge in the charge-transfer direction. The channel stops confine the charge during integration and transfer. See text.

Project Recommendation, Project Initiation, Release for Use, and Retirement are events that must be considered as phase gates or major decision points, and that include formal approvals before development can proceed to the next period. 

Each phase of the SLC must be controlled to maximize the probability that a finished system meets all quality, regulatory, safety, and specification requirements. If an SLC approach is applied properly, no additional work will be required to validate a system. For each SLC period and event, computer systems validation requires that the development processes are documented work products. As explained in Chapter 2, phase gate verification activities performed during each event may be a perfect place to review and quantify the quality of all products needed to support the next phase. 

Validation plans and associated schedules are live documents that should be reviewed periodically. Phase gate verification activities, performed during each event, may be a perfect place to review the project plan and schedule. 

A quantum phase gate for the KLM scheme can be implemented using two such NS gates when the BS has reflection probabilities Rv = 5 — 3 /2 0.76... 

In conclusion, we have presented a reliable method for selective production and detection of high-order atomic polarization moments based on the nonlinear magneto-optical effects with frequency modulated light. This method can be used for the selective control of higher order atomic coherences in multilevel systems exploiting large Kerr nonlinearities for the construction of all-optical quantum phase gates. 

Figure 5. Fidelity of a superposition state (8) as a function of the dimensionless time 7ct. Dot-dashed line static detuning Aa/7c = 0.5. Long-dashed line periodic shifts of the detuning A at from the large value A a/7c = 0.5 to the smaller one As /7c = 0.25 in the sudden change approximation. Solid line periodic shifts and control phase gates. The start and the end of the gate operation are shown by arrows. The rectangle indicates the position of the enlarged view of the right panel.

Many of the activities that have been discussed in the previous chapters are carried out as part of a project. Therefore, it is useful to review some of the basics of project management in the process industries— particularly the Phase/Gate system. 

Factors that affect the phase/gate decision include the following ... 

Charron, E., MUman, R, KeUer, A., and Atabek, O., Quantum phase gate and controlled entanglement with polar molecules, Phys. Rev. A, 75, 033414, 2007. 

For any ( > 0, such a state cannot be written as the product of any single qubit states. Two qubits in such a state are strongly (and nonlocally) correlated. By using a sequence of such phase gates with ( ) = k, and simple unitary operations on a single qubit, any quantum computation can be completed. 

We first describe the generic setup to obtain a phase gate, or universal two-qubit operation, in Figure 17.3 [10]. We assume that the molecules are individually addressable by optical or microwave fields. (Alternatively, a frequency-based addressing scheme akin to the one in the previous section could be used.) We choose 0) and 11) as, for example, hyperfine states within a zero-dipole-moment manifold, in a level with a long coherence time and ) as a metastable state in a large-dipole-moment manifold. 

We now describe three possible setups utilizing variations of our switchable phase-gate scheme [10], The first system is based on carbon monoxide (CO). As far as dipolar molecules are concerned, CO is an anomaly while its electronic ground state X E+ has a very small dipole moment (p. >= 0.1D in the vibrational ground state, which is expected to be the easiest to trap), there exists a very long-lived (xiife lOto 1000 ms)... 

Yelin, S.R, Analysis of experimental feasibility of polar-molecule-based phase gates, Phys. Rev. A, 78, 012313, 2008. 

S. Rebic, D. Vitali, C. Ottaviani, P. Tombesi, M. Artoni, F. Cataliotti, and et al. Polarization phase gate with atripod atomic system. Physical RevewA2004 Sep 21 70(3) 032317(8). 

Ottaviani C, Vital D, Artoni M and et al. Polarization qubit phase gate in driven atomic media. Physical Review Letters 2003 May 15 90(19) 197902(4). 

There are also other three important one-qubit gates, which are the phase gate (S), the 3t/8 (T) gate and the Hadamard gate. The operators S and T are defined by the matrices ... 

Cavity QED has led to many new effects, including the realization of a quantmn phase gate (Turchette et al. 1995), the creation of Fock states of the radiation field (Varcoe et al. 2000), and a demonstration of quantum nondemolition detection of single photons (Nogues et al. 1999). Ye et al. (1999) have noted that all serious schemes for quantum computation and communication via cavity QED rely on developing techniques for atom confinement. This explains the importance of the experiments on the trapping of single atoms under conditions of cavity QED. 

The phase-gate approach to project management is described in Process Risk and Reliability Management. Human factors issues are generally addressed in the first three phases of a project. 

For the preoperative evaluation of potential liver transplant recipients in our institution we perform a multiphasic multidetector CT study, which enables the evaluation of parenchyma and accurate assessment of the arterial, portal venous and hepatic venous anatomy. Oral milk or water (500 ml) is used to opacify the proximal bowel. After a non-intrave-nously enhanced scan is performed, 200 ml of nonionic 350 mg I/ml contrast material is administered intravenously at a 5 ml/s rate. The high iodine concentration allows better visualization of the veins. Acquisition timing is guided by bolus tracking in the aorta (enhancement threshold 200 HU) a late arterial phase scan is initiated 10 s after the threshold is reached, then a venous phase Gate portal-hepatic venous) scan is initiated with a 45-s delay from threshold a delayed acquisition is performed after 3 min. 

---