An optical example for classical Zeno effect

LC Oscillating Circuit as the Simple Classical Analog of the Quantum Zeno Effect

In this work a simple classical analog of the quantum Zeno effect is suggested. As it is well known, in the quantum mechanics, in the limit of the infinite series of alternative short dynamical evolution and measurement, an unstable quantum system will never decay, that is called quantum Zeno effect. Here an ideal (without resistance), classical LC oscillating circuit with quick switch ON-OFF alternation is considered. In the limit of the infinite series of alternative short electrical current regime (switch in the ON state) and no-current regime (current breaking by quick switch ON-OFF state …

Freezing Optical Rogue Waves by Zeno Dynamics

We investigate the Zeno dynamics of the optical rogue waves. Considering their usage in modeling rogue wave dynamics, we analyze the Zeno dynamics of the Akhmediev breathers, Peregrine and Akhmediev-Peregrine soliton solutions of the nonlinear Schrodinger equation. We show that frequent measurements of the wave inhibits its movement in the observation domain for each of these solutions. We analyze the spectra of the rogue waves under Zeno dynamics. We also analyze the effect of observation frequency on the rogue wave profile and on the probability of lingering of the wave in the observation do…

Absorption-free optical control of spin systems:the quantum Zeno effect in optical pumping

We show that atomic spin motion can be controlled by circularly polarized light without light absorption in the strong pumping limit. In this limit, the pumping light, which drives the empty spin state, destroys the Zeeman coherence effectively and freezes the coherent transition via the quantum Zeno effect. It is verified experimentally that the amount of light absorption decreases asymptotically to zero as the incident light intensity is increased.

Non-exponential decay via tunneling in tight-binding lattices and the optical Zeno effect

An exactly-solvable model for the decay of a metastable state coupled to a semi-infinite tight-binding lattice, showing large deviations from exponential decay in the strong coupling regime, is presented. An optical realization of the lattice model, based on discrete diffraction in a semi-infinite array of tunneling-coupled optical waveguides, is proposed to test non-exponential decay and for the observation of an optical analog of the quantum Zeno effect.

Optical Zeno Gate: Bounds for Fault Tolerant Operation

In principle the Zeno effect controlled-sign gate of Franson et al's (PRA 70, 062302, 2004) is a deterministic two-qubit optical gate. However, when realistic values of photon loss are considered its fidelity is significantly reduced. Here we consider the use of measurement based quantum processing techniques to enhance the operation of the Zeno gate. With the help of quantum teleportation, we show that it is possible to achieve a Zeno CNOT gate (GC-Zeno gate) that gives (near) unit fidelity and moderate probability of success of 0.76 with a one-photon to two-photon transmission ratio $κ=10^4$…

Linear and nonlinear quantum Zeno and anti-Zeno effects in a nonlinear optical coupler

Quantum Zeno and anti-Zeno effects are studied in a symmetric nonlinear optical coupler, which is composed of two nonlinear ($χ^{\left(2\right)}$) waveguides that are interacting with each other via the evanescent waves. Both the waveguides operate under second harmonic generation. However, to study quantum Zeno and anti-Zeno effects one of them is considered as the system and the other one is considered as the probe. Considering all the fields involved as weak, a completely quantum mechanical description is provided, and the analytic solutions of Heisenberg's equations of motion for all the f…

A Classical Switched LC/LR Circuit Modeling the Quantum Zeno and Anti-Zeno Effects

Generalizing a recent analysis, we model the quantum Zeno and anti-Zeno effects with a quickly switched, ideal LC/LR circuit, in the limiting case of it alternating very many times between its short LC and even shorter LR regime. If the initial current is arranged to be negligible, the capacitor turns out never to discharge. If the initial current is made dominant, this capacitor discharges, and faster than the exponential decay to which it limits. The existence and simplicity of these phases in such a rudimentary model indicates that the corresponding effects are ubiquitous throughout physics…

Zeno dynamics in wave-packet diffraction spreading

We analyze a simple and feasible practical scheme displaying Zeno, anti-Zeno, and inverse-Zeno effects in the observation of wave-packet spreading caused by free evolution. The scheme is valid both in spatial diffraction of classical optical waves and in time diffraction of a quantum wave packet. In the optical realization, diffraction spreading is observed by placing slits between a light source and a light-power detector. We show that the occurrence of Zeno or anti-Zeno effects depends just on the frequency of observations between the source and detector. These effects are seen to be related…

Observed quantum dynamics: classical dynamics and lack of Zeno effect

We examine a case study where classical evolution emerges when observing a quantum evolution. By using a single-mode quantum Kerr evolution interrupted by measurement of the double-homodyne kind (projecting the evolved field state into classical-like coherent states or quantum squeezed states), we show that irrespective of whether the measurement is classical or quantum there is no quantum Zeno effect and the evolution turns out to be classical.

All-Optical Switching Using the Quantum Zeno Effect and Two-Photon Absorption

We have previously shown that the quantum Zeno effect can be used to implement quantum logic gates for quantum computing applications, where the Zeno effect was produced using a strong two-photon absorbing medium. Here we show that the Zeno effect can also be used to implement classical logic gates whose inputs and outputs are high-intensity fields (coherent states). The operation of the devices can be understood using a quasi-static analysis, and their switching times are calculated using a dynamic approach. The two-photon absorption coefficient of rubidium vapor is shown to allow operation o…

Low-Loss All-Optical Zeno Switch in a Microdisk Cavity Using EIT

We present theoretical results of a low-loss all-optical switch based on electromagnetically induced transparency and the classical Zeno effect in a microdisk resonator. We show that a control beam can modify the atomic absorption of the evanescent field which suppresses the cavity field buildup and alters the path of a weak signal beam. We predict more than 35 dB of switching contrast with less than 0.1 dB loss using just 2 micro-Watts of control-beam power for signal beams with less than single photon intensities inside the cavity.

Exploiting the quantum Zeno effect to beat photon loss in linear optical quantum information processors

We devise a new technique to enhance transmission of quantum information through linear optical quantum information processors. The idea is based on applying the Quantum Zeno effect to the process of photon absorption. By frequently monitoring the presence of the photon through a QND (quantum non-demolition) measurement the absorption is suppressed. Quantum information is encoded in the polarization degrees of freedom and is therefore not affected by the measurement. Some implementations of the QND measurement are proposed.

Improving the Fidelity of Optical Zeno Gates via Distillation

We have modelled the Zeno effect Control-Sign gate of Franson et al (PRA 70, 062302, 2004) and shown that high two-photon to one-photon absorption ratios, $κ$, are needed for high fidelity free standing operation. Hence we instead employ this gate for cluster state fusion, where the requirement for $κ$ is less restrictive. With the help of partially offline one-photon and two-photon distillations, we can achieve a fusion gate with unity fidelity but non-unit probability of success. We conclude that for $κ> 2200$, the Zeno fusion gate will out perform the equivalent linear optics gate.

Optical measurement of electron spins in quantum dots: Quantum Zeno effects

We describe the effects of the quantum back action under continuous optical measurement of electron spins in quantum dots. We consider the system excitation by elliptically polarized light close to the trion resonance, which allows for the simultaneous spin orientation and measurement. We microscopically demonstrate that the nuclei-induced spin relaxation can be both suppressed and accelerated by the continuous spin measurement due to the quantum Zeno and anti-Zeno effects, respectively. Our theoretical predictions can be directly compared with the future experimental results and straightforwa…

A photon loss tolerant Zeno CSIGN gate

We model an optical implementation of a CSIGN gate that makes use of the Quantum Zeno effect [1,2] in the presence of photon loss. The raw operation of the gate is severely affected by this type of loss. However, we show that by using the same photon loss codes that have been proposed for linear optical quantum computation (LOQC), the performance is greatly enhanced and such gates can outperform LOQC equivalents. The technique can be applied to other types of nonlinearities, making the implementation of nonlinear optical gates much more attractive.

Photonic Nonlinearities via Quantum Zeno Blockade

Realizing optical-nonlinear effects at a single-photon level is a highly desirable but also extremely challenging task, because of both fundamental and practical difficulties. We present an avenue to surmounting these difficulties by exploiting quantum Zeno blockade in nonlinear optical systems. Considering specifically a lithium-niobate microresonator, we find that a deterministic phase gate can be realized between single photons with near-unity fidelity. Supported by established techniques for fabricating and operating such devices, our approach can provide an enabling tool for all-optical a…

Engineering steady-state entanglement via dissipation and quantum Zeno dynamics in optical cavity

A new mechanism is proposed for dissipatively preparing maximal Bell entangled state of two atoms in an optical cavity. This scheme integrates the spontaneous emission, the light shift of atoms in the presence of dispersive microwave field, and the quantum Zeno dynamics induced by continuous coupling, to obtain a unique steady state irrespective of initial state. Even for a large cavity decay, a high-fidelity entangled state is achievable at a short convergence time, since the occupation of cavity mode is inhibited by the Zeno requirement. Therefore, a low single-atom cooperativity $C=g^2/(κγ)…

Observation of the Quantum Zeno Effect on a Single Solid State Spin

The quantum Zeno effect, i.e. the inhibition of coherent quantum dynamics by projective measurements is one of the most intriguing predictions of quantum mechanics. Here we experimentally demonstrate the quantum Zeno effect by inhibiting the microwave driven coherent spin dynamics between two ground state spin levels of the nitrogen vacancy center in diamond nano-crystals. Our experiments are supported by a detailed analysis of the population dynamics via a semi-classical model.

Classical Limit of the Quantum Zeno Effect by Environmental Decoherence

We consider a point particle in one dimension initially confined to a finite spatial region whose state is frequently monitored by projection operators onto that region. In the limit of infinitely frequent monitoring, the state never escapes from the region -- this is the Zeno effect. The aim of this paper is to show how the Zeno effect disappears in the classical limit in this and similar examples. We give a general argument showing that the Zeno effect is suppressed in the presence of a decoherence mechanism which kills interference between histories. We show how this works explicitly by cou…

Stability and instability in parametric resonance and quantum Zeno effect

A quantum mechanical version of a classical inverted pendulum is analyzed. The stabilization of the classical motion is reflected in the bounded evolution of the quantum mechanical operators in the Heisenberg picture. Interesting links with the quantum Zeno effect are discussed.

Repeater-assisted Zeno effect in classical stochastic processes

As a classical state, for instance a digitized image, is transferred through a classical channel, it decays inevitably with the distance due to the surroundings' interferences. However, if there are enough number of repeaters, which can both check and recover the state's information continuously, the state's decay rate will be significantly suppressed, then a classical Zeno effect might occur. Such a physical process is purely classical and without any interferences of living beings, therefore, it manifests that the Zeno effect is no longer a patent of quantum mechanics, but does exist in clas…

Quantum description of classical apparatus: Zeno effect and decoherence

We study the measurement process by treating classical detectors entirely quantum mechanically. As a generic model we use a point-contact detector coupled to an electron in a quantum dot and tunneling into the continuum. Transition to the classical description and the mechanism of decoherence are investigated. We concentrate on the influence of the measurement on the electron decay rate to the continuum. We demonstrate that the Zeno (or the anti-Zeno) effect requires a nonuniform density of states in the continuum. In this case we show that the anti-Zeno effect relates only to the average deca…

Classical limit of the quantum Zeno effect

The evolution of a quantum system subjected to infinitely many measurements in a finite time interval is confined in a proper subspace of the Hilbert space. This phenomenon is called "quantum Zeno effect": a particle under intensive observation does not evolve. This effect is at variance with the classical evolution, which obviously is not affected by any observations. By a semiclassical analysis we will show that the quantum Zeno effect vanishes at all orders, when the Planck constant tends to zero, and thus it is a purely quantum phenomenon without classical analog, at the same level of tunn…

Super Mario's prison break -- a proposal of object-intelligent-feedback-based classical Zeno and anti-Zeno effects

Super Mario is imprisoned by a demon in a finite potential well. He can escape from the well with the help of a flight of magic stairs floating in the space. However, the hateful demon may occasionally check his status. At that time, he has to make a judgement of either jumping to the inside ground immediately in order to avoid the discovery of his escape intention, or speeding up his escape process. Therefore, if the demon checks him too frequently such that there is no probability for him to reach the top of the barrier, he will be always inside the well, then a classical Zeno effect occurs.…

Limitations to Realize Quantum Zeno Effect in Beam Splitter Array -- a Monte Carlo Wavefunction Analysis

Effects of non-ideal optical components in realizing quantum Zeno effect in an all-optical setup are analyzed. Beam splitters are the important components in this experimental configuration. Nonuniform transmission coefficient, photon absorption and thermal noise are considered. Numerical simulation of the experiment is performed using the Monte Carlo wavefunction method. It is argued that there is an optimal number of beam splitters to be used for maximizing the expected output in the experiment.

Tunable Tradeoff between Quantum and Classical Computation via Nonunitary Zeno-like Dynamics

We propose and analyze a nonunitary variant of the continuous time Grover search algorithm based on frequent Zeno-type measurements. We show that the algorithm scales similarly to the pure quantum version by deriving tight analytical lower bounds on its efficiency for arbitrary database sizes and measurement parameters. We also study the behavior of the algorithm subject to noise, and find that under certain oracle and operational errors our measurement-based algorithm outperforms the standard algorithm, showing robustness against these noises. Our analysis is based on deriving a non-hermitian…

Interaction-Free All-Optical Switching via Quantum-Zeno Effect

We propose a novel interaction-free scheme for all-optical switching which does not rely on the physical coupling between signal and control waves. The interaction-free nature of the scheme allows it to overcome the fundamental photon-loss limit imposed by the signal-pump coupling. The same phenomenon protects photonic-signal states from decoherence, making devices based on this scheme suitable for quantum applications. Focusing on $χ^{(2)}$ waveguides, we provide device designs for traveling-wave and Fabry-Perot switches. In both designs, the performance is optimal when the signal switching i…

Stabilisation of an optical transition energy via nuclear Zeno dynamics in quantum dot-cavity systems

We investigate the effect of nuclear spins on the phase shift and polarisation rotation of photons scattered off a quantum dot-cavity system. We show that as the phase shift depends strongly on the resonance energy of an electronic transition in the quantum dot, it can provide a sensitive probe of the quantum state of nuclear spins that broaden this transition energy. By including the electron-nuclear spin coupling at a Hamiltonian level within an extended input-output formalism, we show how a photon scattering event acts as a nuclear spin measurement, which when rapidly applied leads to an in…

Comment on "Nonexponential Decay Via Tunneling in Tight-Binding Lattices and the Optical Zeno Effect"

S. Longhi [1] studied the survival probability P(t) of an unstable state coupled to a tight-binding lattice finding an exact analytical solution that describes the nonexponential decay. When the first coupling is smaller than the others, he shows that P(t) has a natural decomposition into two terms; one is the exponential decay, consistent with the Gamow's approach, and the other is the correction to this decay. The first purpose of this Comment is to show that the condition imposed on the system; the site energy of the first site is set in the center of the band, limits the generality of the …

Vacuum state truncation via the quantum Zeno effect

In the context of quantum state engineering we analyze the effect of observation on nonlinear optical $n$-photon Fock state generation. We show that it is possible to truncate the vacuum component from an arbitrary photon number superposition without modifying its remaining parts. In the course of the full dynamical analysis of the effect of observation, it is also found that the Zeno and the anti-Zeno effects repeat periodically. We discuss the close relationship between vacuum state truncation and so-called "interaction-free" measurement.

Driving-induced population trapping and linewidth narrowing via the quantum Zeno effect

We investigate the suppression of spontaneous emission from a driven three-level system embedded in an optical cavity via a manifestation of the quantum Zeno effect. Strong resonant coupling of the lower two levels to an external optical field results in a decrease of the exponential decay rate of the third upper level. We show that this effect has observable consequences in the form of emission spectra with subnatural linewidths, which should be measurable using, for example, quantum dot--cavity systems in currently obtainable parameter regimes. These results constitute a novel method to cont…

Suppressing Hawking radiation by quantum Zeno effect

We present evidence that quantum Zeno effect, otherwise working only for microscopic systems, may also work for large black holes (BH's). The expectation that a BH geometry should behave classically at time intervals larger than the Planck time t_Pl indicates that the quantum process of measurement of classical degrees of freedom takes time of the order of t_Pl. Since BH has only a few classical degrees of freedom, such a fast measurement makes a macroscopic BH strongly susceptible to the quantum Zeno effect, which repeatedly collapses the quantum state to the initial one, the state before the…

Quantum anti-Zeno effect

Prevention of a quantum system's time evolution by repetitive, frequent measurements of the system's state has been called the quantum Zeno effect (or paradox). Here we investigate theoretically and numerically the effect of repeated measurements on the quantum dynamics of the multilevel systems that exhibit the quantum localization of the classical chaos. The analysis is based on the wave function and Schroedinger equation, without introduction of the density matrix. We show how the quantum Zeno effect in simple few-level systems can be recovered and understood by formal modeling the measurem…

On-chip interaction-free measurements via the quantum Zeno effect

Although interference is a classical-wave phenomenon, the superposition principle, which underlies interference of individual particles, is at the heart of quantum physics. An interaction-free measurements (IFM) harnesses the wave-particle duality of single photons to sense the presence of an object via the modification of the interference pattern, which can be accomplished even if the photon and the object haven't interacted with each other. By using the quantum Zeno effect, the efficiency of an IFM can be made arbitrarily close to unity. Here we report an on-chip realization of the IFM based…

Quantum Communication Complexity using the Quantum Zeno Effect

The quantum Zeno effect (QZE) is the phenomenon where the unitary evolution of a quantum state is suppressed e.g. due to frequent measurements. Here, we investigate the use of the QZE in a class of communication complexity problems (CCPs). Quantum entanglement is known to solve certain CCPs beyond classical constraints. However, recent developments have yielded CCPs where super-classical results can be obtained using only communication of a single d-level quantum state (qudit) as a resource. In the class of CCPs considered here, we show quantum reduction of complexity in three ways: using i) e…

Decoherence and the Quantum Zeno Effect

The measurements in the optical test of quantum Zeno effect [Itano et al. Phys. Rev. A\underbar{41} (1990) 2295) are analyzed using the environment-induced decoherence theory, where the spontaneous emission lifetime of the relevant level emerges as the 'decoherence time'. The implication of this finite decoherence time in setting a fundamental limit on the realizability of the condition of continuous measurements is investigated in detail.

Zeno Hall Effect

We show that the quantum Zeno effect gives rise to the Hall effect by tailoring the Hilbert space of a two-dimensional lattice system into a single Bloch band with a nontrivial Berry curvature. Consequently, a wave packet undergoes transverse motion in response to a potential gradient -- a phenomenon we call the Zeno Hall effect to highlight its quantum Zeno origin. The Zeno Hall effect leads to retroreflection at the edge of the system due to an interplay between the band flatness and the nontrivial Berry curvature. We propose an experimental implementation of this effect with ultracold atoms…

Zeno Dynamics and Distinguishability of Quantum States

According to the quantum Zeno effect, the frequent observations of a system can dramatically slow down its dynamical evolution. We show that the Zeno dynamics is the result of projective measurements among quantum states which are indistinguishable. The physical time scale of the problem is provided by the Cramer-Rao lower bound, which measure the distinguishability of states along a path in the Hilbert space. We finally show that the Zeno dynamics with particle entangled states might require quite smaller measurement intervals than classically correlated states, and propose a realistic interf…

耦合至两个线性波导的非简并超拉曼过程中的量子Zeno与anti-Zeno效应

Quantum Zeno and anti-Zeno effects in the dynamics of non-degenerate hyper-Raman processes coupled to two linear waveguides

本文研究了两个探测波导对超拉曼过程动力学的影响，将探测波导通过倏逝波相互作用导致的演化增强或减弱分别视为量子anti-Zeno和Zeno效应，发现该效应与相位匹配或失配相关，但与玻色子模式的反聚束现象无关。

Decoherence, Quantum Zeno Effect, and the Efficacy of Mental Effort

Recent theoretical and experimental papers support the prevailing opinion that large warm systems will rapidly lose quantum coherence, and that classical properties will emerge. This rapid loss of coherence would naturally be expected to block any critical role for quantum theory in explaining the interaction between our conscious experiences and the physical activities of our brains. However, there is a quantum theory of mind in which the efficacy of mental effort is not affected by decoherence effects. In this theory the effects of mental action on brain activity is achieved by a Quantum Zen…

Three components of stochastic entropy production associated with the quantum Zeno and anti-Zeno effects

We investigate stochastic entropy production in a two-level quantum system that performs Rabi oscillations while undergoing quantum measurement brought about by continuous random disturbance by an external measuring device or environment. The dynamics produce quantum Zeno and anti-Zeno effects for certain measurement regimes, and the stochastic entropy production is a measure of the irreversibility of the behaviour. When the strength of the measurement disturbance is time-dependent, the stochastic entropy production separates into three components. Two represent relaxational behaviour, one bei…

通过量子芝诺与反芝诺效应调控局域电子的核诱导自旋弛豫

Tuning the nuclei-induced spin relaxation of localized electrons by the quantum Zeno and anti-Zeno effects

本研究利用量子测量反作用，通过量子芝诺与反芝诺效应分别调控不同体系中局域电子的核诱导自旋弛豫，并明确了两种效应的转变条件。

量子Zeno、Hamlet及类似效应

Quantum Zeno, Hamlet and similar effects

本文基于偏振探测类比和分束器干涉，提出了量子Hamlet效应和anti-Hamlet效应两种新量子效应，并探讨了其与Zeno及anti-Zeno效应的类比关系。

Quantum Zeno subspace and entangled Bose-Einstein condensates

We discuss a proposal for the efficient generation of the maximally entangled atomic N-GHZ state in a spinor-1 condensate by driving internal state atomic Raman transitions using (classical) laser fields. We illustrate the dynamics in terms of a quantum Zeno subspace, and identify the resultant atomic elastic collision in facilitating the deterministic entanglement creation. Our proposal can be readily implemented in several laboratories where ferromagnetic spinor condensates (of $^{87}$Rb atoms) are investigated.

The Quantum Zeno Effect - Evolution of an Atom Impeded by Measurement

The evolution of a quantum system is supposed to be impeded by measurement of an involved observable. This effect has been proven indistinguishable from the effect of dephasing the system's wave function, except in an individual quantum system. The coherent dynamics, on an optical E2 line, of a single trapped ion driven by light of negligible phase drift has been alternated with interrogations of the internal ion state. Retardation of the ion's nutation, equivalent to the quantum Zeno effect, is demonstrated in the statistics of sequences of probe-light scattering ''on'' and ''off'' detections…

Scheme for the protective measurement of a single photon using a tunable quantum Zeno effect

This paper presents a proof-of-principle scheme for the protective measurement of a single photon. In this scheme, the photon is looped arbitrarily many times through an optical stage that implements a weak measurement of a polarization observable followed by a strong measurement protecting the state. The ability of this scheme to realize a large number of such interaction-protection steps means that the uncertainty in the measurement result can be drastically reduced while maintaining a sufficient probability for the photon to survive the measurement.

零点阻塞实现光子量子优化

Zeno Blockade Enabling Photonic Quantum Optimization

本文提出利用非线性光学中的零点效应实现光子量子优化，通过线性协议寻找加权最大独立集，探讨了其作为熵计算范式或量子退火在受限子空间中的应用。

Decoherence and the Quantum Zeno Effect

The experiment of Etano et al which demonstrated the quantum Zeno effect (QZE) in an optical experiment was explained by Frerichs and Schenzle without invoking the wave function collapse. In this report it is proposed that the collapse does occur, and it can be explained by the `environment induced decoherence' theory. The environment here consists of the completely quantized field vacuum modes. The spontaneous emission life time of the atom sets a fundamental limit on the requirement of `continuous measurements' for QZE. This limit turns out to be related to the time-energy uncertainty relati…

Quantum Zeno effect: Quantum shuffling and Markovianity

The behavior displayed by a quantum system when it is perturbed by a series of von Neumann measurements along time is analyzed. Because of the similarity between this general process with giving a deck of playing cards a shuffle, here it is referred to as quantum shuffling, showing that the quantum Zeno and anti-Zeno effects emerge naturally as two time limits. Within this framework, a connection between the gradual transition from anti-Zeno to Zeno behavior and the appearance of an underlying Markovian dynamics is found. Accordingly, although a priori it might result counterintuitive, the qua…

Decoherence and the appearance of classicality in physical phenomena

It is accepted that among the ways through which a quantum phenomenon decoheres and becomes a classical one is what is termed in the literature the Zeno effect. This effect, named after the ancient Greek philosopher Zeno of Elea (born about 485 B.C), were used in 1977 to analytically predict that an initial quantum state may be preserved in time by merely repeating a large number of times, in a finite total time, the experiment of checking its state. Since then this effect has been experimentally validated and has become an established physical fact. It has been argued by Simonius that the Zen…

Zeno Paradox for Bohmian Trajectories: The Unfolding of the Metatron

We analyse the track of an α-particle passing through a cloud chamber using the Bohm theory and show that the resulting classical track has its origins in the quantum Zeno effect. By assuming the ionised gas molecules reveal the positions of the α-particle on its trajectory and using these positions in a short time propagator technique developed by de Gosson, we show it is the failure of the quantum potential to develop quickly enough that leads to the appearance of the classical trajectory. Bohm and Hiley have already argued that it is this failure of the quantum potential to develop appropri…

Zeno极限之外的有效热化界限

Bounds on an effective thermalization beyond the Zeno limit

本文研究有限时间分辨率下量子Zeno效应对经典信息的保护，推导任意操作间隔的有效Zeno动力学，并在多次与极少干预情形下给出信息保存效能界限。

Decoherence Correction by the Zeno Effect and Non-Holonomic Control

We show that multidimensional Zeno effect combined with non-holonomic control allows to efficiently protect quantum systems from decoherence by a method similar to classical coding. Contrary to the conventional approach, our method is applicable to arbitrary error-inducing Hamiltonians and general quantum systems. We also propose algorithms of finding encoding that approaches the Hamming upper bound along with methods of practical realizations of the encodings. Two new codes protecting 2 information qubits out of 7 and 4 information qubits out of 9 against a single error with arbitrarily small…

Freezing a Coherent Field Growth in a Cavity by Quantum Zeno Effect

We have frozen the coherent evolution of a field in a cavity by repeated measurements of its photon number. We use circular Rydberg atoms dispersively coupled to the cavity mode for an absorption-free photon counting. These measurements inhibit the growth of a Field injected in the cavity by a classical source. This manifestation of the Quantum Zeno effect illustrates the back action of the photon number determination onto the Field phase. The residual growth of the Field can be seen as a random walk of its amplitude in the two-dimensional phase space. This experiment sheds light onto the meas…