Quantum Optics: Journal of the European Optical Society Part B, 1992
The thermal photon statistics of the Jaynes-Cummings model are derived. The thermodynamics of the... more The thermal photon statistics of the Jaynes-Cummings model are derived. The thermodynamics of the field-atom system in equilibrium is also studied.
We apply a tomographic method we have recently proposed to the reconstruction of the full entangl... more We apply a tomographic method we have recently proposed to the reconstruction of the full entangled quantum state for the cyclotron and spin degrees of freedom of a trapped electron. Our numerical simulations show that the entangled state is accurately reconstructed. -Pacs: 03.65.
It is shown that a linear Fabry-Perot cavity with an oscillating end mirror can be used as a quan... more It is shown that a linear Fabry-Perot cavity with an oscillating end mirror can be used as a quantum nondemolition measurement device or as a quantum noise eater. For high quality factor of the mechanical oscillator and high mechanical frequency, the output quantum fluctuations of a monocromatic light beam can be significantly squeezed at a frequency very close to that of the impinging light. At lower mechanical frequency, by measuring the statistics of the mechanical momentum, the measurement of the photon number is obtained without the demolition of the quantum state of the light inside the cavity. The analysis is performed by taking into account the coupling of the system with the external world.
We analyze the spectrum of squeezing of the beam reflected by a one-ended empty cavity, treating ... more We analyze the spectrum of squeezing of the beam reflected by a one-ended empty cavity, treating separately the two cases in which the input corresponds to a squeezed vacuum, or to squeezed beam with a mean value much larger than the fluctuations. In the first case the fluctuation ellipse can be rotated at will by varying the cavity length. In
SummaryThe main result of this paper is to exhibit a field-theoretical derivation of the so-calle... more SummaryThe main result of this paper is to exhibit a field-theoretical derivation of the so-called «linear model» for the equation of state of a scalar-field model, valid near the critical point. We introduce a suitable version of the «skeleton expansion technique» that allows us to investigate the critical behaviour as the order parameter and the temperature approach the critical point, both for temperature above and below the critical temperature. We select the first term of such an expansion: the one-loop diagrams. As the dimensionality of the physical space is extended to four,i.e. in the so-called ε limit, we recover up to the first order in ε the results already known in the literature. We finally discuss the validity of results for any ε up to the physical three-dimensional space.RiassuntoIl risultato principale del lavoro è quello di presntare un approccio di teoria dei campi per l'equazione di stato di un campo scalare in prossimità del punto critico. Si introduce un'opportuna versione della tecnica dello «sviluppo scheletro» che permette di analizzare l'andamento critico quando sia il parametro d'ordine che la temperatura si avvicinano ai rispettivi valori al punto critico. Si studia ciò sia per temperature al disopra che al disotto di quella critica. Di tale sviluppo si seleziona il primo termine: il diagramma ad un'ansa. Se la dimensionalità dello spazio è estesa fino a quattro, nel cosidetto limite ε, si ritrovano i risultati al primo ordine dello sviluppo in ε già noti nella letteratura. Infine si discute la validità dei risultati nel caso fisico dello spazio a tre dimensioni.РезюмеОсновной результат этой работы представляет вывод с помощью методов теории поля так называемой «линейной модели» уравнения состояния для модели скалярного поля, которое справедливо вблизи критической точки. Мы вводим соответствующий вариант «техники скелетного разложения», который позволяет нам исследовать критическое човедение, когда параметр упорядоченности и температура приближаются к критической точке, причем, рассмотрение проводится для температур вяше и ниже критической температуры. Мы выбираем первый член такого разложения: диаграммы с одной петлей. Когда размерность физического пространства расширяется до петырех, т.е. в так называемом ε пределе мы возвращаемся с точностью до первого порядка, по ε к результатам уже известным в литературе. В заключение мы обсуждаем сч→аведливость результатов для произвольного ε.
The q-deformation of a single quantized radiation mode interacting with a collection of two level... more The q-deformation of a single quantized radiation mode interacting with a collection of two level atoms is introduced, analyzing its effects on the cooperative behavior of the system.
Quantum Optics: Journal of the European Optical Society Part B, 1992
The thermal photon statistics of the Jaynes-Cummings model are derived. The thermodynamics of the... more The thermal photon statistics of the Jaynes-Cummings model are derived. The thermodynamics of the field-atom system in equilibrium is also studied.
We apply a tomographic method we have recently proposed to the reconstruction of the full entangl... more We apply a tomographic method we have recently proposed to the reconstruction of the full entangled quantum state for the cyclotron and spin degrees of freedom of a trapped electron. Our numerical simulations show that the entangled state is accurately reconstructed. -Pacs: 03.65.
It is shown that a linear Fabry-Perot cavity with an oscillating end mirror can be used as a quan... more It is shown that a linear Fabry-Perot cavity with an oscillating end mirror can be used as a quantum nondemolition measurement device or as a quantum noise eater. For high quality factor of the mechanical oscillator and high mechanical frequency, the output quantum fluctuations of a monocromatic light beam can be significantly squeezed at a frequency very close to that of the impinging light. At lower mechanical frequency, by measuring the statistics of the mechanical momentum, the measurement of the photon number is obtained without the demolition of the quantum state of the light inside the cavity. The analysis is performed by taking into account the coupling of the system with the external world.
We analyze the spectrum of squeezing of the beam reflected by a one-ended empty cavity, treating ... more We analyze the spectrum of squeezing of the beam reflected by a one-ended empty cavity, treating separately the two cases in which the input corresponds to a squeezed vacuum, or to squeezed beam with a mean value much larger than the fluctuations. In the first case the fluctuation ellipse can be rotated at will by varying the cavity length. In
SummaryThe main result of this paper is to exhibit a field-theoretical derivation of the so-calle... more SummaryThe main result of this paper is to exhibit a field-theoretical derivation of the so-called «linear model» for the equation of state of a scalar-field model, valid near the critical point. We introduce a suitable version of the «skeleton expansion technique» that allows us to investigate the critical behaviour as the order parameter and the temperature approach the critical point, both for temperature above and below the critical temperature. We select the first term of such an expansion: the one-loop diagrams. As the dimensionality of the physical space is extended to four,i.e. in the so-called ε limit, we recover up to the first order in ε the results already known in the literature. We finally discuss the validity of results for any ε up to the physical three-dimensional space.RiassuntoIl risultato principale del lavoro è quello di presntare un approccio di teoria dei campi per l'equazione di stato di un campo scalare in prossimità del punto critico. Si introduce un'opportuna versione della tecnica dello «sviluppo scheletro» che permette di analizzare l'andamento critico quando sia il parametro d'ordine che la temperatura si avvicinano ai rispettivi valori al punto critico. Si studia ciò sia per temperature al disopra che al disotto di quella critica. Di tale sviluppo si seleziona il primo termine: il diagramma ad un'ansa. Se la dimensionalità dello spazio è estesa fino a quattro, nel cosidetto limite ε, si ritrovano i risultati al primo ordine dello sviluppo in ε già noti nella letteratura. Infine si discute la validità dei risultati nel caso fisico dello spazio a tre dimensioni.РезюмеОсновной результат этой работы представляет вывод с помощью методов теории поля так называемой «линейной модели» уравнения состояния для модели скалярного поля, которое справедливо вблизи критической точки. Мы вводим соответствующий вариант «техники скелетного разложения», который позволяет нам исследовать критическое човедение, когда параметр упорядоченности и температура приближаются к критической точке, причем, рассмотрение проводится для температур вяше и ниже критической температуры. Мы выбираем первый член такого разложения: диаграммы с одной петлей. Когда размерность физического пространства расширяется до петырех, т.е. в так называемом ε пределе мы возвращаемся с точностью до первого порядка, по ε к результатам уже известным в литературе. В заключение мы обсуждаем сч→аведливость результатов для произвольного ε.
The q-deformation of a single quantized radiation mode interacting with a collection of two level... more The q-deformation of a single quantized radiation mode interacting with a collection of two level atoms is introduced, analyzing its effects on the cooperative behavior of the system.
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