Stability of Single Electron Devices: Charge Offset Drift

Stewart, M. D.; Zimmerman, Neil M.

doi:10.3390/app6070187

Cited by 16 publications

(19 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SETs are considered to be the world's most sensitive electrometers, with the capability of detecting the motion of individual electrons or charge instabilities [13][14][15][16][17] . The same sensitivity that enables exquisite readout of a target qubit is also susceptible to any other charge motion within the local environment, e.g., unintentional charge defects.…”

Section: Reduction Of Charge Offset Drift Using Plasma Oxidized Alumimentioning

confidence: 99%

“…Extensive prior work examining the charge offset stability of various materials showed that metallic SETs incorporating AlO x tunnel barriers demonstrate severe time instability-random, time-dependent phase fluctuations in the control curve [13][14][15][16][17][18] . These large, abrupt changes are attributed to two-level system (TLS) defects associated with amorphous AlO x , consistent with similar findings from TLS spectroscopy studies in the context of superconducting qubits [19][20][21] .…”

Section: Reduction Of Charge Offset Drift Using Plasma Oxidized Alumimentioning

confidence: 99%

See 1 more Smart Citation

Reduction of charge offset drift using plasma oxidized aluminum in SETs

Hong

Stein

Stewart

et al. 2020

Sci Rep

View full text Add to dashboard Cite

Aluminum oxide ($${\text {AlO}}_x$$ AlO x )-based single-electron transistors (SETs) fabricated in ultra-high vacuum (UHV) chambers using in situ plasma oxidation show excellent stabilities over more than a week, enabling applications as tunnel barriers, capacitor dielectrics or gate insulators in close proximity to qubit devices. Historically, $${\text {AlO}}_x$$ AlO x -based SETs exhibit time instabilities due to charge defect rearrangements and defects in $${\text {AlO}}_x$$ AlO x often dominate the loss mechanisms in superconducting quantum computation. To characterize the charge offset stability of our $${\text {AlO}}_x$$ AlO x -based devices, we fabricate SETs with sub-1 e charge sensitivity and utilize charge offset drift measurements (measuring voltage shifts in the SET control curve). The charge offset drift ($$\Delta {Q_0}$$ Δ Q 0 ) measured from the plasma oxidized $${\text {AlO}}_x$$ AlO x SETs in this work is remarkably reduced (best $$\Delta {Q_0}=0.13 \, \hbox {e} \, \pm \, 0.01 \, \hbox {e}$$ Δ Q 0 = 0.13 e ± 0.01 e over $$\approx 7.6$$ ≈ 7.6 days and no observation of $$\Delta {Q_0}$$ Δ Q 0 exceeding $$1\, \hbox {e}$$ 1 e ), compared to the results of conventionally fabricated $${\text {AlO}}_x$$ AlO x tunnel barriers in previous studies (best $$\Delta {Q_0}=0.43 \, \hbox {e} \, \pm \, 0.007 \, \hbox {e}$$ Δ Q 0 = 0.43 e ± 0.007 e over $$\approx 9$$ ≈ 9 days and most $$\Delta {Q_0}\ge 1\, \hbox {e}$$ Δ Q 0 ≥ 1 e within one day). We attribute this improvement primarily to using plasma oxidation, which forms the tunnel barrier with fewer two-level system (TLS) defects, and secondarily to fabricating the devices entirely within a UHV system.

show abstract

Section: Reduction Of Charge Offset Drift Using Plasma Oxidized Alumimentioning

confidence: 99%

Section: Reduction Of Charge Offset Drift Using Plasma Oxidized Alumimentioning

confidence: 99%

Reduction of charge offset drift using plasma oxidized aluminum in SETs

Hong

Stein

Stewart

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…These have been shown to occur due to charge offsets fluctuating over time in glassy media and their intrinsic two-level systems (TLS). 15,16 Finally, unintentional quantum dots, charge traps, or charge defects can influence a desired quantum state. This class of effects can manifest when the scale of the wave function of the charge carriers involved is equal to the scale of (unintended) features or variations in the structure.…”

mentioning

confidence: 99%

A fabrication guide for planar silicon quantum dot heterostructures

Spruijtenburg¹,

Amitonov²,

Wiel³

et al. 2018

Nanotechnology

View full text Add to dashboard Cite

We describe important considerations to create top-down fabricated planar quantum dots in silicon, often not discussed in detail in literature. The subtle interplay between intrinsic material properties, interfaces and fabrication processes plays a crucial role in the formation of electrostatically defined quantum dots. Processes such as oxidation, physical vapor deposition and atomic-layer deposition must be tailored in order to prevent unwanted side effects such as defects, disorder and dewetting. In two directly related manuscripts written in parallel we use techniques described in this work to create depletion-mode quantum dots in intrinsic silicon, and low-disorder silicon quantum dots defined with palladium gates. While we discuss three different planar gate structures, the general principles also apply to 0D and 1D systems, such as self-assembled islands and nanowires. 1 arXiv:1709.08866v3 [cond-mat.mes-hall] Feb 2018Dealing with the fragility of the quantum coherent state is one of the key issues on the road to meet the limits posited by quantum computation schemes 1 . It is the coupling of quantum states to states in an unknown environment which is the driver for decoherence. The properties of the environment therefore dictate the performance of a quantum bit (qubit).Creating qubits in the solid state means that the environment consists of many different materials and structures used in device construction. give rise to interactions detrimental to qubit creation and readout.The hyperfine interaction of nuclear spins in the host material and the qubit is one such effect. The non-zero-spin isotopes in a material create a nuclear-spin-bath and cause decoherence of the quantum state. This is the motivation for the use of isotopically purified silicon as a host material for spin qubits 9,10 . The purified silicon, now containing predomi-Si, results in a zero-nuclear-spin isotope system, and eliminates the fluctuations in the spin bath, which are detrimental.Field noise, such as charge-and spin-noise 11 can also influence the lifetime of the quantum state. One strategy to deal with these fluctuations is to tune the quantum dots to certain regimes in phase space where the energy levels of interest are insensitive to these fields. This can happen in the clock transition of Bi dopants in Si 12 , by dressing qubits and tuning them appropriately 13 , or for hybrid quantum dots. 14 Another effect that can influence quantum states are fluctuations in the electrochemical potential at longer timescales. These have been shown to occur due to charge offsets fluctuating over time in glassy media and their intrinsic two-level systems (TLS). 15,16Finally, unintentional quantum dots, charge traps, or charge defects can influence a de- This article has the intention to provide a foothold for entrants in the field (e.g. starting graduate students) and elucidate mechanisms that need to be taken into account when designing and fabricating these devices in the solid state. It can be read back to front, and may also serve well ...

show abstract

“…These have been shown to occur due to charge offsets fluctuating over time in glassy media and their intrinsic twolevel systems (TLS). 34,70 Finally, unintentional quantum dots, charge traps, or charge defects can influence a desired quantum state. This class of effects can manifest when the scale of the wavefunction of the charge carriers involved is equal to the scale of (unintended) features or variations in the structure.…”

Section: Quantum Dot Heterostructuresmentioning

confidence: 99%

“…168 One of the ways to extract the charge offset is by taking the trace of a number of Coulomb oscillations as a function of gate voltage V g . The oscillations are modelled as a function of regularly interspaced peaks and fitted using the following general formula: 70 I D (V g ) = A 0 + A sin (2πV g /∆V g +Q 0 (t )/e) + BV g (7.1) with A 0 the base current, A the amplitude of the peaks, B accounts for a linear increase of background current. The charge offset is given as Q 0 = phase ∆V g e, with ∆V g the periodicity of the Coulomb oscillations.…”

Section: Confinementmentioning

confidence: 99%

Imperfection : holes and defects in silicon quantum dots

Spruijtenburg¹

View full text Add to dashboard Cite

Dit proefschrift is goedgekeurd door de promotor: prof. dr. ir. W.G. van der Wiel Finally, I get to thank my parents in writing. Mama, Papa, thank you for always providing a safe environment and for giving me the opportunity to look at the glistening pieces on the shores, valleys, and countless mountains. Thank you, for listening and supporting me through my stints of youthful exhuberance. Just the three of us. To all the perfectly imperfect,

show abstract

Stability of Single Electron Devices: Charge Offset Drift

Cited by 16 publications

References 55 publications

Reduction of charge offset drift using plasma oxidized aluminum in SETs

Reduction of charge offset drift using plasma oxidized aluminum in SETs

A fabrication guide for planar silicon quantum dot heterostructures

Imperfection : holes and defects in silicon quantum dots

Contact Info

Product

Resources

About