A tunable few electron triple quantum dot

Gaudreau, Louis; Kam, A.; Granger, G.; Studenikin, Sergei; Zawadzki, Piotr; Sachrajda, A. S.

doi:10.1063/1.3258663

Cited by 80 publications

(89 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Few-electron triple quantum dots [13][14][15] have been used to realize charge reconfigurations corresponding to the elementary operations of quantum cellular automata 16 , although tunable spin interactions have not yet been demonstrated 17 .…”

Section: Introductionmentioning

confidence: 99%

Coherent spin manipulation in an exchange-only qubit

Laird¹,

Taylor²,

DiVincenzo³

et al. 2010

Phys. Rev. B

238

304

View full text Add to dashboard Cite

Initialization, manipulation, and measurement of a three-spin qubit are demonstrated using a few-electron triple quantum dot, where all operations can be driven by tuning the nearest-neighbor exchange interaction. Multiplexed reflectometry, applied to two nearby charge sensors, allows for qubit readout. Decoherence is found to be consistent with predictions based on gate voltage noise with a uniform power spectrum. The theory of the exchange-only qubit is developed and it is shown that initialization of only two spins suffices for operation. Requirements for full multi-qubit control using only exchange and electrostatic interactions are outlined.Comment: related work at http://marcuslab.harvard.ed

show abstract

Section: Introductionmentioning

confidence: 99%

Coherent spin manipulation in an exchange-only qubit

Laird¹,

Taylor²,

DiVincenzo³

et al. 2010

Phys. Rev. B

238

304

View full text Add to dashboard Cite

show abstract

“…The procedure might therefore be extended to few-electron triple QD circuits which include a charge detector. [31][32][33][34] …”

Section: Discussionmentioning

confidence: 99%

Determination of energy scales in few-electron double quantum dots

Taubert

Schuh

Wegscheider

et al. 2011

Review of Scientific Instruments

View full text Add to dashboard Cite

The capacitive couplings between gate-defined quantum dots and their gates vary considerably as a function of applied gate voltages. The conversion between gate voltages and the relevant energy scales is usually performed in a regime of rather symmetric dot-lead tunnel couplings strong enough to allow direct transport measurements. Unfortunately, this standard procedure fails for weak and possibly asymmetric tunnel couplings, often the case in realistic devices. We have developed methods to determine the gate voltage to energy conversion accurately in the different regimes of dot-lead tunnel couplings and demonstrate strong variations of the conversion factors. Our concepts can easily be extended to triple quantum dots or even larger arrays.

show abstract

“…Therefore all dots have to be emptied and one needs to control them in the so called "few-electron regime". Up to now, only three dots in series have been demonstrated to be tunable [9,10] in the few-electron regime. A triple quantum dot geometry in a star-like configuration has been demonstrated, but the geometry did not allow tunneling between all close-by dots and the few-electron regime was not reached [11].…”

Section: Pacs Numbersmentioning

confidence: 99%

A few-electron quadruple quantum dot in a closed loop

Thalineau

Hermelin

Wieck

et al. 2012

Applied Physics Letters

View full text Add to dashboard Cite

We report the realization of a quadruple quantum dot device in a square-like configuration where a single electron can be transferred on a closed path free of other electrons. By studying the stability diagrams of this system, we demonstrate that we are able to reach the few-electron regime and to control the electronic population of each quantum dot with gate voltages. This allows us to control the transfer of a single electron on a closed path inside the quadruple dot system. This work opens the route towards electron spin manipulation using spin-orbit interaction by moving an electron on complex paths free of electrons. PACS numbers:Controlling the path of a single electron in semiconducting nanostructures is an interesting tool in the context of spin qubits systems. In particular, it opens the route towards the transport of quantum information on a chip and represents a potential strategy to scale up the number of spin qubits in interaction [1]. In addition, in presence of spin-orbit interaction, it represents an interesting way to manipulate coherently the spin of a single electron [2][3][4]. Recently, fast and efficient single electron transport could be obtained by assisting the transport through a 1D-channel electrostatically defined with surface acoustic waves on AlGaAs heterostructures [5,6]. Nevertheless, such a technique is restricted to displacements on a straight line. To perform more complex displacements, engineering the path of the electron with series of quantum dots is a promising alternative. In this context, it has been demonstrated that topological spin manipulation can be obtained if the electron is transported adiabatically on a closed path under spin-orbit interaction [7,8].In order to preserve spin information during transport, all other electrons of the heterostructure potentially present along the electron path have to be removed. Therefore all dots have to be emptied and one needs to control them in the so called "few-electron regime". Up to now, only three dots in series have been demonstrated to be tunable [9,10] in the few-electron regime. A triple quantum dot geometry in a star-like configuration has been demonstrated, but the geometry did not allow tunneling between all close-by dots and the few-electron regime was not reached [11].Here we present the first step towards the transfer of a single electron spin on a closed path using a series of quantum dots in a square-like geometry. We demonstrate that we are able to set the system in the few-electron regime using charge detection techniques and therefore to remove the other electrons along the path. Moreover, the tunability of the four-dot system allows a single electron to be transported along a closed path isolated from the other electrons of the structure. The quantum dot system is fabricated using a GaAs/AlGaAs heterostructure grown by molecular beam epitaxy, with a two-dimensional electron gas (2DEG) 100nm below the surface (density 2 × 10 11 cm −2 and mobility 1 × 10 6 V −1 s −1 ). By applying negative voltages to the meta...

show abstract

A tunable few electron triple quantum dot

Cited by 80 publications

References 18 publications

Coherent spin manipulation in an exchange-only qubit

Coherent spin manipulation in an exchange-only qubit

Determination of energy scales in few-electron double quantum dots

A few-electron quadruple quantum dot in a closed loop

Contact Info

Product

Resources

About