2,703 research outputs found

### Impossibility of distant indirect measurement of the quantum Zeno effect

We critically study the possibility of quantum Zeno effect for indirect
measurements. If the detector is prepared to detect the emitted signal from the
core system, and the detector does not reflect the signal back to the core
system, then we can prove the decay probability of the system is not changed by
the continuous measurement of the signal and the quantum Zeno effect never
takes place. This argument also applies to the quantum Zeno effect for
accelerated two-level systems, unstable particle decay, etc.Comment: 14 pages, 2 figure

### Influence of the detector's temperature on the quantum Zeno effect

In this paper we study the quantum Zeno effect using the irreversible model
of the measurement. The detector is modeled as a harmonic oscillator
interacting with the environment. The oscillator is subjected to the force,
proportional to the energy of the measured system. We use the Lindblad-type
master equation to model the interaction with the environment. The influence of
the detector's temperature on the quantum Zeno effect is obtained. It is shown
that the quantum Zeno effect becomes stronger (the jump probability decreases)
when the detector's temperature increases

### Quantum Zeno effect with a superconducting qubit

Detailed schemes are investigated for experimental verification of Quantum
Zeno effect with a superconducting qubit. A superconducting qubit is affected
by a dephasing noise whose spectrum is 1/f, and so the decay process of a
superconducting qubit shows a naturally non-exponential behavior due to an
infinite correlation time of 1/f noise. Since projective measurements can
easily influence the decay dynamics having such non-exponential feature, a
superconducting qubit is a promising system to observe Quantum Zeno effect. We
have studied how a sequence of projective measurements can change the dephasing
process and also we have suggested experimental ways to observe Quantum Zeno
effect with a superconducting qubit. It would be possible to demonstrate our
prediction in the current technology

### From the quantum Zeno to the inverse quantum Zeno effect

The temporal evolution of an unstable quantum mechanical system undergoing
repeated measurements is investigated. In general, by changing the time
interval between successive measurements, the decay can be accelerated (inverse
quantum Zeno effect) or slowed down (quantum Zeno effect), depending on the
features of the interaction Hamiltonian. A geometric criterion is proposed for
a transition to occur between these two regimes.Comment: 6 pages, 3 figure

### NMR analogues of the quantum Zeno effect

We describe Nuclear Magnetic Resonance (NMR) demonstrations of the quantum
Zeno effect, and discuss briefly how these are related to similar phenomena in
more conventional NMR experiments.Comment: 8 pages including 4 figures; intended as a possible answer to Malcolm
Levitt's question at the 2005 Magnetic Resonanace GRC: "What is the NMR
analogue of the quantum Zeno effect?". In press at Physics Letters

### Demonstration of quantum Zeno effect in a superconducting phase qubit

Quantum Zeno effect is a significant tool in quantum manipulating and
computing. We propose its observation in superconducting phase qubit with two
experimentally feasible measurement schemes. The conventional measurement
method is used to achieve the proposed pulse and continuous readout of the
qubit state, which are analyzed by projection assumption and Monte Carlo
wave-function simulation, respectively. Our scheme gives a direct
implementation of quantum Zeno effect in a superconducting phase qubit.Comment: 5 pages, 4 figure

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