Smart Materials and Structures

Single-electron transistor architectures for charge motion detection in solid-state quantum computer devices

T M B hler, R. Brenner, D. J. Reilly, A. R. Hamilton, Andrew S. Dzurak, R. G. Clark

Published Sep 20, 2002• 3 citations

Abstract

Single-spin detection will be crucial for solid-state quantum computer (QC) architectures in which information is encoded in the spin state of single nuclear or electron spins. The formidable problem of single-spin detection in a solid can be mapped to a more tractable problem of single-charge detection through spin-dependent electron transfer which may be observed using ultrasensitive solid-state nanostructure electrometers. Here we describe a read-out architecture using single-electron transistors (SETs) that can detect the charge state of two coupled metal dots, which simulates charge transfer in a two-quantum-bit (qubit) spin system. This twin-SET architecture allows significant reduction of random charge noise by correlating two detector outputs, reducing the probability of read-out errors in the QC.

DOI: 10.1088/0964-1726/11/5/319

Related papers

Nanoscale single-electron transistor architectures for single spin detection in solid state quantum computer devices

Tilo M. Buehler, R. Brenner, D. J. Reilly +3 more

Single-spin detection will be crucial for solid-state quantum computer architectures in which information is encoded in the spin-state of single nuclear or electron spins. The formidable problem of single-spin detection in a solid can be mapped to a more tractable problem of single-charge detection through spin-dependent electron transfer which may be observed using ultra-sensitive solid-state nanostructure electrometers. Here we describe a readout architecture using single electron transistors (SETs) that can detect the charge-state of two coupled metal dots, which simulates charge transfer in a two-quantum bit (qubit) spin system. This twin-SET architecture allows significant reduction of random charge noise by correlating two detector outputs, reducing the probability of readout errors in the quantum computer.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIENov 19, 20010 citations

Correlated charge detection for readout of a solid-state quantum computer

Tilo M. Buehler, D. J. Reilly, R. Brenner +3 more

The single-electron transistor (SET) is a prime candidate for reading out the final state of a qubit in a solid-state quantum computer. Such a measurement requires the detection of subelectron charge motion in the presence of random charging events. We present a detection scheme where the signals from two SETs are cross-correlated to suppress unwanted artifacts due to charge noise. This technique is demonstrated by using the two SETs to detect the charge state of two coupled metal dots, thereby simulating charge transfer and readout in a two-qubit system. These measurements indicate that for comparable buried dopant semiconductor architectures, the minimum measurement time required to distinguish between the two charge states is of the order of 10 ns.

arXiv:cond-mat/0207597Applied Physics LettersJan 23, 200342 citations

Modelling single-electron-transistor-based readout in the Kane solid-state quantum computer

Chris I. Pakes, Vincent I. Conrad, J C Ang +5 more

The Kane (Kane B E 1998 Nature 393 133) solid-state quantum computer aims to exploit as qubits an array of 31 P nuclear spins embedded in a silicon matrix. A proposed scheme for readout of a qubit spin state relies on measurement of the associated spin state of its donor electron, by attempting to induce and detect, using a single-electron transistor (SET), spin-polarized motion of the electron to an adjacent donor site. The sensitivity required of a SET for detection of sub-surface electronic charge motion in a MOS architecture is examined by simulation of the capacitive coupling of the buried charge to the SET device. It is shown that the SET can support readout of the qubit electronic charge states within the appropriate electron spin relaxation time. This paper presents a novel application of Technology Computer Aided Design, which presents itself as a valuable tool for the design of nanoscale device architectures employing precision electrometry for readout of quantum logic states.

NanotechnologyJan 10, 20035 citations

Multiplexing single electron transistors for application in scalable solid-state quantum computing

Vincent I. Conrad, Andrew D. Greentree, Lloyd C. L. Hollenberg

Single electron transistors (SETs) are nanoscale electrometers of unprecedented sensitivity, and as such have been proposed as readout devices in a number of quantum computer architectures. The authors show that the functionality of a standard SET can be multiplexed so as to operate as both readout device and control gate for solid-state qubit systems based on charge localization and spin-charge transduction. Such multiplexing offers new possibilities for gate density reduction in nanoscale devices, and may therefore play a role in scalable quantum computer architectures.

arXiv:cond-mat/0608652Applied Physics LettersJan 22, 20077 citations

A High-Sensitivity Charge Sensor for Silicon Qubits above 1 K

Jonathan Y. Huang, Wee Han Lim, Ross C. C. Leon +6 more

Recent studies of silicon spin qubits at temperatures above 1 K are encouraging demonstrations that the cooling requirements for solid-state quantum computing can be considerably relaxed. However, qubit readout mechanisms that rely on charge sensing with a single-island single-electron transistor (SISET) quickly lose sensitivity due to thermal broadening of the electron distribution in the reservoirs. Here we exploit the tunneling between two quantized states in a double-island single-electron transistor (SET) to demonstrate a charge sensor with an improvement in the signal-to-noise ratio by an order of magnitude compared to a standard SISET, and a single-shot charge readout fidelity above 99% up to 8 K at a bandwidth greater than 100 kHz. These improvements are consistent with our theoretical modeling of the temperature-dependent current transport for both types of SETs. With minor additional hardware overhead, these sensors can be integrated into existing qubit architectures for a high-fidelity charge readout at few-kelvin temperatures.

arXiv:2103.06433Nano LettersMay 17, 202114 citations

Improved Single-Shot Qubit Readout Using Twin rf-SET Charge Correlations

Santiago Serrano, MengKe Feng, Wee Han Lim +11 more

High-fidelity qubit readout is critical in order to obtain the thresholds needed to implement quantum error-correction protocols and achieve fault-tolerant quantum computing. Large-scale silicon qubit devices will have densely packed arrays of quantum dots with multiple charge sensors that are, on average, farther away from the quantum dots, entailing a reduction in readout fidelities. Here, we present a readout technique that enhances the readout fidelity in a linear SiMOS four-dot array by amplifying correlations between a pair of single-electron transistors, known as a twin SET. By recording and subsequently correlating the twin SET traces as we modulate the dot detuning across a charge transition, we demonstrate a reduction in the charge readout infidelity by over one order of magnitude compared to traditional readout methods. We also study the spin-to-charge conversion errors introduced by the modulation technique and conclude that faster modulation frequencies avoid relaxation-induced errors without introducing significant spin-flip errors, favoring the use of the technique at short integration times. This method not only allows for faster and higher-fidelity qubit measurements but it also enhances the signal corresponding to charge transitions that take place farther away from the sensors, enabling a way to circumvent the reduction in readout fidelities in large arrays of qubits. Published by the American Physical Society 2024

arXiv:2307.07724PRX QuantumJan 3, 20247 citations