Numerical Study on Aging Dynamics in the 3D Ising Spin-Glass Model. III. Cumulative Memory and `Chaos' Effects in the Temperature-Shift Protocol

The temperature ($T$)-shift protcol of aging in the 3 dimensional (3D) Edwards- Anderson (EA) spin-glass (SG) model is studied through the out-of-phase component of the ac susceptibility simulated by the Monte Carlo method. For processes with a small magnitude of the $T$-shift, $\Delta T$, the memory imprinted before the $T$-shift is preserved under the $T$-change and the SG short-range order continuously grows after the $T$-shift, which we call the cumulative memory scenario. For a negative $T$-shift process with a large $\Delta T$ the deviation from the cumulative memory scenario has been observed for the first time in the numerical simulation. We attribute the phenomenon to the `chaos effect' which, we argue, is qualitatively different from the so-called rejuvenation effect observed just after the $T$-shift.Comment: 8 pages, 5 figure

General relativistic Sagnac formula revised

The Sagnac effect is a time or phase shift observed between two beams of light traveling in opposite directions in a rotating interferometer. We show that the standard description of this effect within the framework of general relativity misses the effect of deflection of light due to rotational inertial forces. We derive the necessary modification and demonstrate it through a detailed analysis of the square Sagnac interferometer rotating about its symmetry axis in Minkowski space-time. The role of the time shift in a Sagnac interferometer in the synchronization procedure of remote clocks as well as its analogy with the Aharanov-Bohm effect are revised.Comment: 11 pages, 3 figure

Anisotropic Stark Effect and Electric-Field Noise Suppression for Phosphorus Donor Qubits in Silicon

We report the use of novel, capacitively terminated coplanar waveguide (CPW) resonators to measure the quadratic Stark shift of phosphorus donor qubits in Si. We confirm that valley repopulation leads to an anisotropic spin-orbit Stark shift depending on electric and magnetic field orientations relative to the Si crystal. By measuring the linear Stark effect, we estimate the effective electric field due to strain in our samples. We show that in the presence of this strain, electric-field sources of decoherence can be non-negligible. Using our measured values for the Stark shift, we predict magnetic fields for which the spin-orbit Stark effect cancels the hyperfine Stark effect, suppressing decoherence from electric-field noise. We discuss the limitations of these noise-suppression points due to random distributions of strain and propose a method for overcoming them

Improved theory for the polarization-dependent transverse shift of a paraxial light beam in free space

Spatial distribution of the longitudinal field component of a circularly polarized optical beam depends on the polarization handedness, which causes the lateral shift of the beam "center of gravity" when its polarization toggles. We present the generalized theory of this effect, which demonstrates its relation with the angular irradiance moments of the beam. The theory is applicable to arbitrary paraxial beams and shows that the lateral shift is the same for all cross sections of the beam.Comment: 9 pages, 2 figures. The paper is submitted to Ukr. J. Phys. Opt. It contains the refined and generalized theory of the effect first observed and explained by B. Zel'dovich et al. in 1994: polarizxation-dependent transverse shift of the focal spot obtained by focusing an asymmetric light bea