Ground State of a Polaron in a Symmetric Triangular Quantum Well

We study the effects of electron-phonon interaction on the electron ground state in a symmetric triangular quantum well, and calculate the ground state energy of an electron in the GaAs/Al0.96Ga0.04As triangular quantum well including the effects of the interaction between electrons and confined LO phonons by using a modified Lee-Low-Pines variational method. The electron wavefunction in the triangular well is chosen as the Airy function. The numerical results are given and discussed.     

Steady State of the Dusty Plasma in a dc Discharge

The steady state formed by the diffusion of plasma particles in an inhomogeneous dusty plasma is investigated theoretically and compared with our previous experimental results [Nucl.Fusion Plasma Phys.20(2000)180 (in Chinese);Phys.Plasmas 8(2001)1459].The negatively charged dust grains with an average charge number of the order of 10^5 on a single grain enhance the plasma inhomogeneity by decreasing the diffusion velocity,and can cause significant depletion of electrons.The theoretical electron density profile is in good agreement with the experiment,and the theoretical profile of the electron-to-ion density ratio is in reasonable agreement with experimentally estimated data.     

Nonclassical Spatial State of an Atom in a Quantized Trap

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Coexistence of Zero-Dimensional Electride State and Superconductivity in AlH2 Monolayer

Elect rides,which confine "excess anionic electrons" in subnanometer-sized cavities of a lattice,are exotic ionic crystals.We propose a non-stoichiometric strategy to realize intrinsic two-dimensional(2D) superconducting elect ride.AlH₂ monolayer,which is structurally identical to 1H-MoS₂,possesses zero-dimensionally confined anionic electrons in the interstitial sites of A1 triangles,corresponding to a chemical formula of [AlH₂]⁺e^-.The inte...     

Quantum State Sharing of an Arbitrary Two-Atom State by Using a?Six-Atom Cluster State in Cavity QED

We demonstrate that a six-atom cluster state can be used to realize the deterministic quantum state sharing of an arbitrary two-atom state in cavity QED. The scheme does not involve Bell-state measurement and is insensitive to both the cavity decay and the thermal field. In our scheme, any one of the two agents is sufficient to reconstruct the original state under the condition that he/she obtains the help of the other one, but only one of them cannot.     

Stretch-Bender Calculations of the Rovibronic Energies in the Excited, ÃA1, Electronic State of NH2 and of the Near-Resonant High-Lying Levels of the X?B1 State

The extended stretch-bender Hamiltonian, incorporating spin-orbit coupling and overall rotation, has been used to calculate the spin-vibronic structure of the rovibronic energies in the region where the vibronic states of the excited òA₁ electronic state of NH₂ interact with near-resonant high-lying levels of the X?²B₁ state of NH₂. A detailed comparison has been made with the experimental measurements which were made of these rovibronic states, the majority of which are due to Ramsay, Vervloet, and their collaborators. We have shown that, as in our study of the vibronic levels of the X?²B₁ state below the barrier to linearity, in order to fit the variation of the effective vibronic spin-orbit coupling constant over the whole of this energy regime, the effective linear molecule spin-orbit coupling constant, A_SO must be increased from the earlier value of 50 cm⁻¹ of Ch. Jungen, K.-E. J. Hallin, and A. Merer (Mol. Phys.40, 65-94 (1980)) to 61.6 cm⁻¹. The impact of Fermi resonance, in both the òA₁ and X?²B₁ states, on the observed rovibronic structure has been assessed. The pattern of calculated spin-rovibronic levels, including the effects of spin uncoupling, is in good agreement with that measured experimentally.     

Stretch-Bender Calculations of the Rovibronic Energies in the X?B1 Electronic Ground State of NH2

The extended stretch-bender Hamiltonian, incorporating spin-orbit coupling and overall rotation, has been used to calculate the spin-vibronic structure of the X?²B₁ state of NH₂ up to the barrier to linearity of this state. A detailed comparison has been made with experimental measurements of these rovibronic states, the majority of which are due to Vervloet and his collaborators. We have shown that, in order to fit the variation of the vibronic spin-orbit coupling constant over the whole of this energy regime, the effective linear molecule spin-orbit coupling constant, A_SO, must be increased from the earlier value of 50 cm⁻¹ of Ch. Jungen, K.-E. J. Hallin, and A. Merer (Mol. Phys.40, 65-94 (1980)) to 61.6 cm⁻¹. Evidence has also been provided for the large quenching of the spin-orbit coupling as the molecule bends, reflected in the large valuee of g_K=6 cm⁻¹. The pattern of calculated spinrovibronic levels, including the effects of spin uncoupling, is in good agreement with that measured experimentally.     

Equation of State of 20Ne gas in the temperature-range 27–36 K

The many-body phase shifts for ²⁰Ne gas are calculated for low number densities in the temperature-range 27–36?K, using the Galitskii-Migdal-Feynman formalism. These phase shifts are inserted in the Beth-Uhlenbeck formula to determine the quantum second virial coefficient. This is compared to the classical coefficient as well as to the experimental values and other theoretical results. It is used to investigate the pressure-volume-temperature behavior of the gas and to compute other thermodynamic properties – the Helmholtz free energy, total internal energy, entropy, and specific heat capacity – for a number density of 1×?10²⁷ atoms/m³. Our results show that, in cooling and compressing the system, vapor-liquid condensation always occurs.     

Vibration-Torsion-Rotation Study of the ν5 State of CH3CF3

An investigation of the torsion-rotation-vibration energies in the ν₅ vibrational state in CH₃CF₃ has been carried out using infrared and mm-wave spectroscopy. The lowest frequency parallel fundamental band ν₅ near 600 cm⁻¹ has been measured at a resolution of 0.00125 cm⁻¹ with Fourier transform spectroscopy for the two lowest torsional states v₆=0 and 1. The cold band (v₅=1, v₆=0)←(v₅=0, v₆=0) showed no torsional splittings and looked much like a parallel band in a C_3v molecule. The hot band (v₅=1, v₆=1)←(v₅=0, v₆=1) consisted of three distinct subbands, one for each torsional sublevel σ=0, +1, and −1. For the state (v₅=1, v₆=1), the torsional splitting was increased from ∼0.001 cm⁻¹ to ∼0.022 cm⁻¹ by torsion-mediated Fermi-type interaction primarily with the dark state (v₅=0, v₆=5). The effects of this coupling on the spectrum are striking in spite of the fact that the two interacting states are ∼100 cm⁻¹ apart and differ by four units in v₆. The large amplitude character of the state (v₅=0, v₆=5) is seen to be largely responsible for the unusual (k, σ) dependence of the energies in the state (v₅=1, v₆=1). The pure rotational spectrum in the state (v₅=1, v₆=0) has been measured between ∼50 and 370 GHz with Doppler-limited resolution; no σ-splitting was detected. The 3590 infrared and mm-wave frequencies measured here have been analyzed together with the 1494 measurements reported earlier by Wang et al. in an analysis of the vibrational ground state (2001, J. Mol. Spectrosc.205, 146-163). A good fit was obtained here by varying 36 parameters in a Hamiltonian which takes into account the interaction between the torsional stacks of levels for v₅=0 and 1, as well as the (A₁−A₂) splittings measured earlier for v₅=0. The explicit treatment of the interstack interactions is shown to lead to significant changes in the parameters (V_0,3, V_0,6) that characterize the torsional potential for v₅=0. These changes have been explained quantitatively by examining the contact transformation that is implicitly applied when the interstack coupling is neglected.     

Quantum Poincare Section of a Two—Dimensional Hamiltonian in a Coherent State Representation

We study the quantum behaviour of a quasi-integrable Hamiltonian.The unperturbed Hamiltonian displays degeneracies of energy levels,which become avoided crossing under a nonintegrable perturbation.In this two-dimensional system,the quantum Poincare section plot is constructed in the coherent state representation with the restriction that the centres of the wavepackets are confined at thd classical surface of constant energy.It is found that the quantum Poincare section plot obtained in this way provides an evident counterpart of the classical system.     

Revisiting “Quantum State Sharing of an Arbitrary Two-Atom State by Using a Six-Atom Cluster State in Cavity QED”

In Nie et al. (Int. J. Theor. Phys. 50: 2526, 2011), authors put forward a cavity QED scheme for deterministic quantum state sharing (QSTS) of an arbitrary two-atom state. They claimed that, the quantum channel of the QSTS scheme is a six-atom cluster state. After simple calculation, one can see that the quantum channel they used is a direct product of two three-atom GHZ states. In this paper, we propose a cavity QED scheme for QSTS of an arbitrary two-atom state via a six-atom cluster state channel. In our scheme, two two-atom Bell state measurements are transformed into the discrimination of single-atom product states. Moreover, the two-atom unitary operation is changed to single-qubit unitary operations. Our scheme is insensitive to the cavity decay. The necessary time for the scheme is much shorter than the Rydberg-atom lifespan, therefore atom decays do not need to be considered.     

Quantum Fluctuation of Mesoscopic Capacitance Coupled Circuit in a Thermal Vacuum State

The quantum fluctuations of mesoscopic capacitance-coupled circuit in thermal vacuum state are investigated by using the theory of thermal field dynamics on the basis of quantization of the mesoscopic circuit. It is shown that under a definite temperature, the fluctuations of electric charges and currents change with temperature. The higher the temperature, the more quantum noise the coupled circuit exhibits.     

Preparation of Multi—Atom Entangled States with a Single Cavity in a Thermal State

A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermal state,In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonant cavity.We divide the whole atom-cavity interaction time into two equal parts.At the end of the first part a π pulse is applied to the atome using a classical field.Then the photon-number-dependent shifts on the atomic states are cancelled and the atomic system finally evoloves to a maximally entangled state.     

A Theoretical Study of MgNC and MgCN in the X?Σ Electronic State

The MgNC radical was the first Mg-containing species to be observed in interstellar space. This fact has stimulated considerable spectroscopic interest in this molecule, and in its isomer MgCN, but nevertheless the only rotationally resolved spectroscopic data presently available for X?²Σ⁺ MgNC comprise the rotational spectrum (K. Kawaguchi et al., 1993, Astrophys. J.406, L39-L42; K. Ishii et al., 1993, Astrophys. J.410, L43-L44; M. A. Anderson and L. M. Ziurys, 1994, Chem. Phys. Lett.231, 164-170; E. Kagi et al., 1996, J. Chem. Phys.104, 1263-1267; E. Kagi and K. Kawaguchi, J. Mol. Spectrosc. 2000, 199, 309-310) together with a few vibronic bands, all originating in the vibronic ground state and belonging to the òΠ←X?²Σ⁺ electronic transition (R. R. Wright and T. A. Miller, 1999, J. Mol. Spectrosc.194, 219-228). For MgCN, only the rotational spectrum in the vibrational ground state is known (M. A. Anderson, T. C. Steimle, and L. M. Ziurys, 1994, Astrophys. J.429, L41-L44). We report here potential energy surfaces calculated by the Averaged Coupled-Pair Functional (ACPF) method with TZ3P+f (Mg), TZ2P+f(N,C) basis sets including core-valence correlation due to the Mg 2s and 2p electrons. The ab initio results are used for determining the standard spectroscopic constants of X?²Σ⁺ MgNC and MgCN. Also, we report variational calculations of the rotation-vibration energies, and variational simulations of the lowest rotation-vibration bands, carried out with the MORBID program system (P. Jensen, 1988, J. Mol. Spectrosc.128, 478-501). We hope that our theoretical results will encourage and facilitate further characterization of X?²Σ⁺ MgNC and MgCN by high-resolution spectroscopy.     

Ground State of Fermions in a 1D Trap with δ Function Interaction

The ground state of fermions in a 1D trap with δ function interaction is studied mathematically with group theory ideas.     

Intracavity Laser Spectroscopy of NiCl System G: Identification of a [13.0] Π3/2 State

The (0,0) vibronic band of NiCl system G with a bandhead near 12 961 cm⁻¹ was recorded at high resolution in absorption using intracavity laser spectroscopy (ILS). For the ILS absorption spectra, the NiCl molecules were produced in a nickel hollow cathode, operated with a small amount of CCl₄, and line positions were referenced to iodine spectra. Fourier transform (FT) emission spectroscopy was used to record an extensive region of the spectrum used in a vibronic analysis of system G. For the FT spectra, excited NiCl molecules were produced in a high-temperature King-type carbon tube furnace. We show that this transition is the (0,0) vibronic band associated with a newly identified ²Π_3/2 excited state and the X²Π_3/2 ground state. The molecular constants for the new ²Π_3/2 electronic state are derived from the rotational analysis. Improved vibronic constants for the band are obtained from analysis of the FT spectra.     

Quantum Logic Network for Probabilistic Teleportation of Two-Particle State in a General Form

A simplification scheme of probabilistic teleportation of two-particle state in a general form is given.By means of the primitive operations consisting of single-qubit gates,two-qubit controlled-not gates,Von Neumann measure-ment and classically controlled operations,we construct and efficient quantum logical network for implementing the new scheme of probabilistic teleportation of a two-particle state in a general form.     

Teleportation of a Quantum State Entangled with Environment

A quantum state of a fermion entangled with the thermal environment is constructed by doubling the Fock space.The teleportation of the state entangled with the thermal environment is also discussed.