6533b862fe1ef96bd12c76ee

RESEARCH PRODUCT

Measuring charge based quantum bits by a superconducting single-electron transistor

Jami J. KinnunenJukka P. PekolaPäivi Törmä

subject

PhysicsCharge qubitCondensed matter physicsPhysicsCondensed Matter - Superconductivitysingle-electron transistorMultiple-emitter transistorFOS: Physical sciencesHardware_PERFORMANCEANDRELIABILITYsuperconductorsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectThreshold voltagePhase qubitSuperconductivity (cond-mat.supr-con)superconductorsingle-electron transistorsComputer Science::Emerging TechnologiesHardware_GENERALOptical transistorHardware_INTEGRATEDCIRCUITScharge-based quantum bitsField-effect transistorSuperconducting quantum computingStatic induction transistorHardware_LOGICDESIGN

description

Single-electron transistors have been proposed to be used as a read-out device for Cooper pair charge qubits. Here we show that a coupled superconducting transistor at a threshold voltage is much more effective in measuring the state of a qubit than a normal-metal transistor at the same voltage range. The effect of the superconducting gap is to completely block the current through the transistor when the qubit is in the logical state 1, compared to the mere diminishment of the current in the normal-metal case. The time evolution of the system is solved when the measuring device is driven out of equilibrium and the setting is analysed numerically for parameters accessible by lithographic aluminium structures.

yearjournalcountryeditionlanguage
2002-11-08
10.1103/physrevb.68.020506http://arxiv.org/abs/cond-mat/0211154