5 Path Integrals in Quantum Mechanics and Quantum Field Theory
... and the sum over histories q(t) is restricted by the boundary conditions q(ti ) = qi and q(tf ) = qf . Notice now that the Feynman path-integral tells us that in the correspondence limit ! → 0, the only history (or possibly histories) that contribute significantly to the path integral must be those ...
... and the sum over histories q(t) is restricted by the boundary conditions q(ti ) = qi and q(tf ) = qf . Notice now that the Feynman path-integral tells us that in the correspondence limit ! → 0, the only history (or possibly histories) that contribute significantly to the path integral must be those ...
Exchange bias NiO Co
... Spin reorientation at the antiferromagnetic NiO(001) surface in response to an adjacent ferromagnet H. Ohldag, A. Scholl, F. Nolting, S. Anders, F.U. Hillebrecht, and J. Stöhr ...
... Spin reorientation at the antiferromagnetic NiO(001) surface in response to an adjacent ferromagnet H. Ohldag, A. Scholl, F. Nolting, S. Anders, F.U. Hillebrecht, and J. Stöhr ...
... material, Na4Ir3O8, has Ir ions that form a three-dimensional network of corner-sharing triangles, termed a hyper-Kagome structure (11). Despite an exchange energy of ~300 K, no magnetic order was found down to 1 K and below. It is an exciting time in the history of antiferromagnetism. After decades ...
spin networks and the bracket polynomial
... Here the small diagrams stand for otherwise identical parts of larger diagrams, and the second formula means that any Jordan curve disjoint from the rest of the diagram contributes a factor of d to the polynomial. This recursive description of the bracket is well-defined so long as the variables A, ...
... Here the small diagrams stand for otherwise identical parts of larger diagrams, and the second formula means that any Jordan curve disjoint from the rest of the diagram contributes a factor of d to the polynomial. This recursive description of the bracket is well-defined so long as the variables A, ...
On the Statistical Meaning of Complex Numbers in Quantum
... Komogorovian model is implicit in Wigner’s proof of Bell’s inequality(10) (in Bell’s original proof, correlations rather than conditional probabilities are considered(11)). In general one can prove (cf.(2,4)) that if the conditional probabilities satisfy (2)—as is always the case in quantum theory—t ...
... Komogorovian model is implicit in Wigner’s proof of Bell’s inequality(10) (in Bell’s original proof, correlations rather than conditional probabilities are considered(11)). In general one can prove (cf.(2,4)) that if the conditional probabilities satisfy (2)—as is always the case in quantum theory—t ...
Bose-Einstein condensation in interacting gases
... existence of a crossover between two regimes, at low and high densities; at low densities the critical temperature is indeed increased – but even in this region the results do not really agree with any of the analytical calculations mentioned above – see also reference [33] for another discussion of ...
... existence of a crossover between two regimes, at low and high densities; at low densities the critical temperature is indeed increased – but even in this region the results do not really agree with any of the analytical calculations mentioned above – see also reference [33] for another discussion of ...
Two interacting spin particles - Dipartimento di Matematica e Fisica
... The z component of the total angular momentum J z 5L z 1M z ~which is the same as the unperturbed Hamiltonian H 0 ) obeys the selection rules DJ z 50,62\, so the subspace spanned by the states with odd J z /\ can be separated from that with J z /\ even ~there are no matrix elements for the transitio ...
... The z component of the total angular momentum J z 5L z 1M z ~which is the same as the unperturbed Hamiltonian H 0 ) obeys the selection rules DJ z 50,62\, so the subspace spanned by the states with odd J z /\ can be separated from that with J z /\ even ~there are no matrix elements for the transitio ...
Low-Temperature Phase Diagrams of Quantum Lattice
... perturbation theory, in order to clarify the purely algebraic aspects of this theory in a context where all our formal expansions are actually given by norm-convergent series. We consider a finite interval of the spectrum of the Hamiltonian which is separated from the rest of the spectrum by a spect ...
... perturbation theory, in order to clarify the purely algebraic aspects of this theory in a context where all our formal expansions are actually given by norm-convergent series. We consider a finite interval of the spectrum of the Hamiltonian which is separated from the rest of the spectrum by a spect ...
6 Product Operators
... between these energy levels which are detected in spectroscopy. To understand the spectrum, therefore, it is necessary to have a knowledge of the energy levels and this in turn requires a knowledge of the Hamiltonian operator. In NMR, the Hamiltonian is seen as having a more subtle effect than simpl ...
... between these energy levels which are detected in spectroscopy. To understand the spectrum, therefore, it is necessary to have a knowledge of the energy levels and this in turn requires a knowledge of the Hamiltonian operator. In NMR, the Hamiltonian is seen as having a more subtle effect than simpl ...
6 Product Operators
... these energy levels which are detected in spectroscopy. To understand the spectrum, therefore, it is necessary to have a knowledge of the energy levels and this in turn requires a knowledge of the Hamiltonian operator. In NMR, the Hamiltonian is seen as having a more subtle effect than simply determ ...
... these energy levels which are detected in spectroscopy. To understand the spectrum, therefore, it is necessary to have a knowledge of the energy levels and this in turn requires a knowledge of the Hamiltonian operator. In NMR, the Hamiltonian is seen as having a more subtle effect than simply determ ...
Quantum networks in the presence of D B
... lattice, containing nodes with different coordination numbers, we contrast the diamond chain with a square ladder, i.e. a chain of square loops connected at two vertices, (the inset of Fig. 2). In the following, we will also refer to the latter topology simply as the ladder. The formalism to study t ...
... lattice, containing nodes with different coordination numbers, we contrast the diamond chain with a square ladder, i.e. a chain of square loops connected at two vertices, (the inset of Fig. 2). In the following, we will also refer to the latter topology simply as the ladder. The formalism to study t ...
Stochastic semiclassical cosmological models
... To a certain extent, quantum fluctuations may be introduced in a classical model as uncertainty in the initial conditions. However, fluctuations play a subtler role when the semiclassical evolution, as is in fact the rule, is dissipative @7,8#. In this case, the semiclassical gravitational field int ...
... To a certain extent, quantum fluctuations may be introduced in a classical model as uncertainty in the initial conditions. However, fluctuations play a subtler role when the semiclassical evolution, as is in fact the rule, is dissipative @7,8#. In this case, the semiclassical gravitational field int ...
Mott insulator of ultracold alkaline-earth-metal-like atoms
... It is important to realize a MI phase in Yb for the following reasons. First, Yb is an excellent candidate for an optical lattice clock 关4,5兴. The absolute frequency of the 1S0- 3 P0 transition in bosonic 174Yb atoms has been recently determined within a fractional uncertainty of 1.5⫻ 10−15 关6兴. The ...
... It is important to realize a MI phase in Yb for the following reasons. First, Yb is an excellent candidate for an optical lattice clock 关4,5兴. The absolute frequency of the 1S0- 3 P0 transition in bosonic 174Yb atoms has been recently determined within a fractional uncertainty of 1.5⫻ 10−15 关6兴. The ...
Selection rules for nonradiative carrier relaxation processes in
... form a spin singlet in their ground level but the two holes, one in the ground level and one in an excited level, form spin triplets [Fig. 1(d)]. These configurations are spin blockaded from further phonon-assisted relaxations and therefore result in distinct photoluminescence (PL) emission lines (F ...
... form a spin singlet in their ground level but the two holes, one in the ground level and one in an excited level, form spin triplets [Fig. 1(d)]. These configurations are spin blockaded from further phonon-assisted relaxations and therefore result in distinct photoluminescence (PL) emission lines (F ...
Ph. D. Thesis
... study the interlayer dimer state in spin-S bilayer antiferromagnets. At a critical bilayer coupling strength, condensation of triplet excitations leads to Neel order. In describing ii ...
... study the interlayer dimer state in spin-S bilayer antiferromagnets. At a critical bilayer coupling strength, condensation of triplet excitations leads to Neel order. In describing ii ...
Berry phases near degeneracies: Beyond the simplest
... these points in mind helps distinguish the Berry magnetic field from the true one. We now discuss why the Chern number must be an integer. The argument is basically the same as that given by Dirac in his proof that the existence of a 共true兲 magnetic monopole implies the quantization of electric char ...
... these points in mind helps distinguish the Berry magnetic field from the true one. We now discuss why the Chern number must be an integer. The argument is basically the same as that given by Dirac in his proof that the existence of a 共true兲 magnetic monopole implies the quantization of electric char ...
Universal Long-Time Behavior of Nuclear Spin Decays in a Solid
... 129 Xe polarized to 5%–10% were prepared using spinexchange convection cells [7,29]. FIDs and solid echoes were acquired at 77 K in an applied field of 1.5 T (129 Xe Larmor frequency of 17.6 MHz), well into the high-field limit of Eq. (2). The enormous dynamic range of these signals required a separ ...
... 129 Xe polarized to 5%–10% were prepared using spinexchange convection cells [7,29]. FIDs and solid echoes were acquired at 77 K in an applied field of 1.5 T (129 Xe Larmor frequency of 17.6 MHz), well into the high-field limit of Eq. (2). The enormous dynamic range of these signals required a separ ...
conductivity in half-filled ionic hubbard model
... the atomic limit (t = 0). In this case, when U < 2∆ the sites with lower energy −∆ are doubly occupied and those with higher energy +∆ are empty, therefore the IHM is a band insulator. In contrast, when U > 2∆ both types of sites are singly occupied and the IHM is a MI. At the single special value U ...
... the atomic limit (t = 0). In this case, when U < 2∆ the sites with lower energy −∆ are doubly occupied and those with higher energy +∆ are empty, therefore the IHM is a band insulator. In contrast, when U > 2∆ both types of sites are singly occupied and the IHM is a MI. At the single special value U ...
Solution of the Lindblad equation for spin helix states arXiv
... non-neighbouring bonds. The complete absence of correlations in the SHS is reminiscent of very high temperatures. We caution, however, not to interpret this lack of correlations and the flat energy profile along the chain as indicating proximity to some equilibrium state ρ ∝ exp (−βef f H) with an e ...
... non-neighbouring bonds. The complete absence of correlations in the SHS is reminiscent of very high temperatures. We caution, however, not to interpret this lack of correlations and the flat energy profile along the chain as indicating proximity to some equilibrium state ρ ∝ exp (−βef f H) with an e ...
Statistical Physics - damtp
... We’ll start by considering an isolated system with fixed energy, E. For the purposes of the discussion we will describe our system using the language of quantum mechanics, although we should keep in mind that nearly everything applies equally well to classical systems. In your first two courses on ...
... We’ll start by considering an isolated system with fixed energy, E. For the purposes of the discussion we will describe our system using the language of quantum mechanics, although we should keep in mind that nearly everything applies equally well to classical systems. In your first two courses on ...
Statistical Physics - damtp
... We’ll start by considering an isolated system with fixed energy, E. For the purposes of the discussion we will describe our system using the language of quantum mechanics, although we should keep in mind that nearly everything applies equally well to classical systems. In your first two courses on ...
... We’ll start by considering an isolated system with fixed energy, E. For the purposes of the discussion we will describe our system using the language of quantum mechanics, although we should keep in mind that nearly everything applies equally well to classical systems. In your first two courses on ...