Abstract. We review the density of states and related quantities of quasi one-dimensional disordered Peierls systems in which fluctuation effects of a backscattering potential play a crucial role. The low-energy behavior of non-interacting fermions which are subject to a static random backscattering potential will be described by the fluctuating gap model (FGM). Recently, the FGM has also been ...

The magnetic entropy change ( SM) in a single crystal of the geometrically frustrated spin chain system Ca3Co2O6 has been determined under the influence of a wide range of temperatures and magnetic field variations. Our findings are consistent with the spin-density wave description of the zero field order, and with the suppression of the modulated state at low field. Metamagnetic transitions to...

A growing number of mammal species are recognized as heterothermic, capable of maintaining a high-core body temperature or entering a state of metabolic suppression known as torpor. Small mammals can achieve large energetic savings when torpid, but they are also subject to ecological costs. Studying torpor use in an ecological and physiological context can help elucidate relative costs and bene...

We have carried out a preliminary analysis of shot noise at hopping, focusing on uniform one-dimensional ~1D! arrays of sites separated by N tunnel barriers. The results show that at low temperatures the low-frequency density of the shot noise varies from 1/N to 1 of the Schottky value, depending on the geometry, electron density, and Coulomb interaction strength. An interesting feature is v de...

It is widely believed that the Quantum Choromodynamics (QCD) exhibits a phase transition at some temperature Tc, and quarks and gluons confined in the low temperature phase are liberated to form “quark gluon plasma”. At the beginning of 2000, CERN reported that the QGP state had been created in the heavy ion collision experiment[1]. In this experiment, the J/ψ suppression [2] is regarded as a k...

We describe a new quasi-optical SIS mixer designed for efficient radiation coupling. The mixer uses a twinslot antenna which has the advantages of a good beam pattern and a low impedance. The radiation and impedance characteristics of the antenna were obtained from a moment-method calculation. Tapered superconducting microstrip transmission lines are used to carry the radiation from the slot an...

We investigated electron transport through an ultrasmall Si quantum dot. The B dependence of energy levels is dominated by the Zeeman shift, allowing us to measure the spin difference between two successive ground states directly. Combined with the ability to change the number of electrons N in the dot between 0 and 30, we are able to map the spin of the dot as a function of N and B. The dot be...

A theory accounting for the dynamical aspects of the superfluid response of one dimensional (1D) quantum fluids is reported. In long 1D systems, the onset of superfluidity is related to the dynamical suppression of quantum phase slips at low temperatures. The effect of this suppression as a function of frequency and temperature is discussed within the framework of the experimentally relevant mo...

We show that, for fermionic atoms in a one-dimensional optical lattice, the fraction of atoms in doubly occupied sites is a highly nonmonotonic function of temperature. We demonstrate that this property persists even in the presence of realistic harmonic confinement, and that it leads to a suppression of entropy at intermediate temperatures that offers a route to adiabatic cooling. Our interpre...