SOLID

Tuning single GaAs quantum dots in resonance with a rubidium vapor

Date: 
2010-08-23
Author(s): 

N. Akopian, U. Perinetti, L. Wang, A. Rastelli, O. G. Schmidt, and V. Zwiller

Reference: 

Appl. Phys. Lett. 97, 082103 (2010)

We study single GaAs quantum dots with optical transitions that can be brought into resonance with the widely used D2 transitions of rubidium atoms. We achieve resonance by Zeeman or Stark shifting the quantum dot levels. We discuss an energy stabilization scheme based on the absorption of quantum dot photoluminescence in a rubidium vapor. This offers a scalable means to counteract slow spectral diffusion in quantum dots.

Single quantum dot nanowire photodetectors

Date: 
2010-09-16
Author(s): 

M. P. van Kouwen, M. H. M. van Weert, M. E. Reimer, N. Akopian, U. Perinetti, R. E. Algra, E. P. A. M. Bakkers, L. P. Kouwenhoven, and V. Zwiller

Reference: 

Appl. Phys. Lett. 97, 113108 (2010)

Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings

Date: 
2010-08-11
Author(s): 

F. Ding, N. Akopian, B. Li, U. Perinetti, A. Govorov, F. M. Peeters, C. C. Bof Bufon, C. Deneke1, Y. H. Chen, A. Rastelli, O. G. Schmidt, and V. Zwiller

Reference: 

Phys. Rev. B 82, 075309 (2010)

Wide InP superlattice wires with Wurtzite/Zincblende segments are type-II whereas narrower wires become type-I: An atomistic pseudopotential calculation

Date: 
2010-09-01
Author(s): 

Lijun Zhang, Jun-Wei Luo, Alex Zunger, Nika Akopian, Val Zwiller, and Jean-Christophe Harmand

Reference: 

Nanoletters 4055, 10 (2010)

Nanowire-superlattices with different structural phases along the nanowire direction, such as wurtzite (WZ) and zincblende (ZB) forms of the same compound, often exhibit a “type II” band-alignment with electrons on ZB and holes on WZ. This is a material property of most of III−V semiconductors.

Universal Dynamical Decoupling of a Single Solid-State Spin from a Spin Bath

Date: 
2010-09-09
Author(s): 

G. de Lange, Z. H. Wang, D. Ristè, V. V. Dobrovitski and R. Hanson

Reference: 

Science 330, 60 (2010)

Controlling the interaction of a single quantum system with its environment is a fundamental challenge in quantum science and technology. We strongly suppressed the coupling of a single spin in diamond with the surrounding spin bath by using double-axis dynamical decoupling. The coherence was preserved for arbitrary quantum states, as verified by quantum process tomography. The resulting coherence time enhancement followed a general scaling with the number of decoupling pulses.

Reentrance Effect in Macroscopic Quantum Tunneling and Nonadiabatic Josephson Dynamics in d-Wave Junctions

Date: 
2010-09-16
Author(s): 

J. Michelsen and V. S. Shumeiko

Reference: 

Phys. Rev. Lett. 105, 127001 (2010)

Nonadiabatic Josephson dynamics in junctions with in-gap quasiparticles

Date: 
2010-10-01
Author(s): 

J. Michelsen and V. S. Shumeiko

Reference: 

Low Temp. Phys. 36, 925 (2010)

Analysis of a tunable coupler for superconducting phase qubits

Date: 
2010-09-28
Author(s): 

Ricardo A. Pinto, Alexander N. Korotkov, Michael R. Geller, Vitaly S. Shumeiko, John M. Martinis

Reference: 

Phys. Rev. B 82, 104522 (2010)

Floquet theory of Cooper pair pumping

Date: 
2011-06-06
Author(s): 

A. Russomanno, S. Pugnetti, V. Brosco, and R. Fazio

Reference: 

Phys. Rev. B 83, 214508 (2011)

We derive a general formula for the charge pumped in a superconducting nanocircuit. Our expression generalizes previous results in several ways; it is applicable in both the adiabatic and in the nonadiabatic regimes and it takes into account also the effect of an external environment. More specifically, by applying Floquet theory to Cooper pair pumping, we show that under a cyclic evolution the total charge transferred through the circuit is proportional to the derivative of the associated Floquet quasi-energy with respect to the superconducting phase difference.

Syndicate content