arXiv subjects

S. Pilla

Publications and source records attributed to S. Pilla.

4 recordsLinked to original sources

arXiv2001

Using Electrons on Liquid Helium for Quantum Computing

We describe a quantum computer based on electrons supported by a helium film and localized laterally by small electrodes just under the helium surface. Each qubit is made of combinations of the ground and first excited state of an electron trapped in the image potential well at the surface. Mechanisms for preparing the initial state of the qubit, operations with the qubits, and a proposed readout are described. This system is, in principle, capable of 100,000 operations in a decoherence time.

quant-ph↗

arXiv2000

Electric field induced memory and aging effects in pure solid N_2

We report combined high sensitivity dielectric constant and heat capacity measurements of pure solid N_2 in the presence of a small external ac electric field in the audio frequency range. We have observed strong field induced aging and memory effects which show that field cooled samples may be prepared in a variety of metastable states leading to a free energy landscape with experimentally ``tunable'' barriers, and tunneling between these states may occur within laboratory time scales.

cond-mat.dis-nn↗

arXiv2000

A modified dual-slope method for heat capacity measurements of condensable gases

A high resolution non-adiabatic method for measuring the heat capacity ($C_v$) of bulk samples of condensable gases in the range 7.5-70 K is described. In this method $C_v$ is evaluated by directly comparing the heating and cooling rates of the sample temperature for two algebraically independent heat pulse sequences without explicit use of the thermal conductance between sample and thermal bath. A fully automated calorimeter for rapid measurement of $C_v$ of molecular solids utilizing this technique is presented.

cond-mat.mtrl-sci↗

arXiv1999

Dielectric anomalies of solid CO and N_2 in the audio frequency range

We report the first audio frequency dielectric constant measurements of CO and N_2 in their solid phases. We have observed several new features, including (1) strong hysteresis effects above an onset temperature $T_{h} \simeq 42 K$ in the β-phase of pure N_2, (2) absence of the expected short range antiferroelectric dipolar ordering in CO down to 4.2 K, and (3) anomalous temperature dependence of the dielectric constant in the α-phases of both CO and N_2. Quantum mechanical treatment of the molecular rotation explains some of the observed anomalies in the α-phase, but the strong hysteresis indicates that pure geometrical frustration plays a significant role in the β-phase.

cond-mat.mtrl-sci↗