Volume Effect of Bound States in Quark-Gluon Plasma

Bound states, such as qq and q^-q, may exist the volume of the bound states may evoke a reduction in investigate qualitatively the volume effect on the properties states start to be completely melted.     

Scheme for Robust Storage of Multi-particle Entanglement with a Cavity QED System

We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.     

Scheme for Robust Storage of Multi-particle Entanglement with a Cavity QED System

We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.     

More nonlocality with less purity

Quantum information is nonlocal in the sense that local measurements on a composite quantum system, prepared in one of many mutually orthogonal states, may not reveal in which state the system was prepared. It is shown that in the many copy limit this kind of nonlocality is fundamentally different for pure and mixed quantum states. In particular, orthogonal mixed states may not be distinguishable by local operations and classical communication, no matter how many copies are supplied, whereas any set of N orthogonal pure states can be perfectly discriminated with m copies, where m相似文献   

Volume Effect of Bound States in Quark-Gluon Plasma

Bound states, such as qq and q(q), may exist in quark-gluon plasma. As the system is at high density,the volume of the bound states may evoke a reduction in the phase space. We introduce an extended bag model to investigate qualitatively the volume effect on the properties of the system. We find a limit temperature where the bound states start to be completely melted.     

Study of the structures of four-quark states in terms of the Born-Oppenheimer approximation

In this work,we use the Born-Oppenheimer approximation,where the potential between atoms can be approximated as a function of distance between the two nuclei,to study the four-quark bound states.By this approximation,Heitler and London calculated the spectrum of the hydrogen molecule,which includes two protons(heavy)and two electrons(light).Generally,the observed exotic mesons Zb(10610),Zb(10650),Zc(3900)and Zc(4020)(Zc(4025))may be molecular states made of two physical mesons and/or diquark-anti-diquark structures.Analogous to the Heitler-London method for calculating the mass of the hydrogen molecule,we investigate whether there exist energy minima for these two structures.Contrary to the hydrogen molecule case where only the spin-triplet possesses an energy minimum,there exist minima for both of these states.This implies that both molecule and tetraquark states can be stable objects.Since they have the same quantum numbers,however,the two states may mix to result in the physical states.A consequence would be that partner exotic states co-existing with Zb(10610),Zb(10650),Zc(3900)and Zc(4020)(Zc(4025))are predicted and should be experimentally observed.     

Polarization orthogonalization properties of optical systems

We investigate the conditions under which an optical system (or device) may transform polarization states at its input into orthogonal states at its output. We find that such polarization orthogonalization is possible if the Jones matrix of the optical system satisfies a specific inequality. One, two, or an infinite number of input polarization states may be orthogonalized. In the latter case, the locus of input states is a circle in the complex plane (and on the Poincaré sphere) of polarization. Several examples are given for illustration.     

Fast polariton relaxation in strongly coupled organic microcavities

We consider the regime of strong light-matter coupling in an organic microcavity, where large Rabi splitting can be achieved. As has been shown, the excitation spectrum of such a structure, besides coherent polaritonic states, contains a number of strongly spatially localized incoherent excited states. These states form the majority of the excited states of the microcavity and are supposed to play the decisive role in the relaxation dynamics of the excitations in the microcavity. We consider the non-radiative transition from an incoherent excited state into one of the coherent states of the lower polaritonic branch accompanied by emission of a high-energy intramolecular phonon. It is shown that this process may determine the lifetime of incoherent excited states in the microcavity. This observation may be important in the discussion of pump–probe experiments with short pulses. This process may also play an important role for the population of the lowest energy states in organic microcavities, and hence in the problem of condensation of cavity polaritons.     

Two-vibron bound states in the β--Fermi--Pasta--Ulam model

This paper studies the two-vibron bound states in the β- Fermi Pasta-Ulam model by means of the number conserving approximation combined with the number state method. The results indicate that on-site, adjacent-site and mixed two-vibron bound states may exist in the model. Specially, wave number has a significant effect on such bound states, which may be considered as the quantum effects of the localized states in quantum systems.     

利用三粒子纠缠态建立量子隐形传态网络的探讨

利用W态纠缠源可以产生三纠缠粒子，用这些相互纠缠的粒子作为量子信道，再辅以经典信道传送Bell基联合测量信息和von Neumann测量信息，便可实现量子隐形传态网络.基于上述思想，研究了三纠缠粒子量子隐形传态网络的物理基础，得到了基于三粒子W 关键词： 量子通信 量子隐形传态 W态')" href="#">W态     

Photofield emission: An explanation of the rapid oscillations with applied field

We argue that emission from a band of surface states (these states being final states in the photo-excitation process) on a small-area-plane of the field emission tip, may be the cause of the observed rapid oscillations with the applied field of the photofield current.     

Quantum Hall states of high symmetry

We identify some hidden symmetries of Chern-Simons theories, such as appear in the effective theory for quantized Hall states. This allows us to determine which filling fractions admit spin-singlet quantum Hall states. Our results shed some light on states already observed at , and transitions between them. We identify SU(2), or higher, symmetries of many additional states — including spin-polarized states. Our symmetries classify low-lying excited states and may be of use in the construction of trial wavefunctions, but are typically not present in the edge theory, where they are lifted by non-universal couplings.     

Statistics of states generated by quantum-scissors device

Generating desired states is a prerequisite in quantum information. Some desired states can be generated by a quantum-scissors device(QSD). We present a detailed analysis of the properties of the generated states, including average photon numbers and intensity gains. The theoretical analysis shows that there is a nondeterministic amplification in terms of the average photon number under the condition that the average photon number of the input state is less than 1. In contrast to the input states, the generated states show the nonclassical property described by the negativity of the Wigner function. Furthermore, we generalize the QSD to truncate arbitrary photon number terms of the input states, which may be useful in high-dimensional quantum information processing.     

Final-state effects in the excitation spectra of deep impurities in semiconductors

The excitation spectra of deep impurities have usually been interpreted in terms of transitions to continuum states having the same energy distribution and Bloch-like character as the perfect-crystal band states. Here we provide theoretical analysis and experimental evidence showing that deep-level spectra may in fact be dominated by bound and quasibound final states induced by the strong short-range impurity potentials.     

Remote state preparation: arbitrary remote control of photon polarization

We experimentally demonstrate the first remote state preparation of arbitrary single-qubit states, encoded in the polarization of photons generated by spontaneous parametric down-conversion. Utilizing degenerate and nondegenerate wavelength entangled sources, we remotely prepare arbitrary states at two wavelengths. Further, we derive theoretical bounds on the states that may be remotely prepared for given two-qubit resources.     

Origination of entangled states upon interaction of atoms with narrow-band light

Generation and transformation of entangled states in a system of two-level atoms with relaxation interacting with light are considered. It is found that excitation by single-mode squeezed light produces mixed atomic states that prove to be nonseparable. For the field in the Fock state, there may arise Greenberger-Horne-Zeilinger states comprised of atoms and photons. On the basis of the exact solutions of the multiparticle problem, the generation and transformation of atomic states of the W class, including recording of the photon state, are discussed.     

Continuous Pump Assisted Conditional Synthesis of Nonclassical States in a Dispersive Cavity QED

The interaction of N identical atoms with both a quantized cavity field and an external classical pumpingfield with the fields being degenerate in frequency, is studied in the regime where the atoms and fields are highly detuned.This dispersive interaction can be used to generate coherent states for the cavity field. By preparing the injected atomsin a superposition of the bare atomic states, various types of Schrodinger-cat-like states may be generated.     

On the possibility of phase transitions in the geometric structure of space-time

It is shown that space-time may be not only in a state which is described by Riemann geometry but also in states which are described by Finsler geometry. Transitions between various metric states of space-time have the meaning of phase transitions in its geometric structure. These transitions together with the evolution of each of the possible metric states make up the general picture of space-time manifold dynamics.     

Simulation of the Ising model,memory for Bell states and generation of four-atom entangled states in cavity QED

A scheme is proposed to simulate the Ising model and preserve the maximum entangled states (Bell states) in cavity quantum electrodynamics (QED) driven by a classical field with large detuning. In the strong driving and large-detuning regime, the effective Hamiltonian of the system is the same as the standard Ising model, and the scheme can also make the initial four Bell states of two atoms at the maximum entanglement all the time. So it is a simple memory for the maximal entangled states. The system is insensitive to the cavity decay and the thermal field and more immune to decoherence. These advantages can warrant the experimental feasibility of the current scheme. Furthermore, the genuine four-atom entanglement may be acquired via two Bell states through one-step implementation on four two-level atoms in the strong-driven model, and when two Greenberger-Horne-Zeilinger (GHZ) states are prepared in our scheme, the entangled cluster state may be acquired easily. The success probability for the scheme is 1. Supported by the National Natural Science Foundation of China (Grant No. 10774088) and the Key Program of the National Natural Science Foundation of China (Grant No. 10534030)     

Interaction of regular and chaotic states

Modelling the chaotic states in terms of the Gaussian Orthogonal Ensemble of random matrices (GOE), we investigate the interaction of the GOE with regular bound states. The eigenvalues of the latter may or may not be embedded in the GOE spectrum. We derive a generalized form of the Pastur equation for the average Green’s function. We use that equation to study the average and the variance of the shift of the regular states, their spreading width, and the deformation of the GOE spectrum non-perturbatively. We compare our results with various perturbative approaches.