Quantum theory of the charge-stability diagram of semiconductor double-quantum-dot systems

Wang, Xin; Yang, Shuming; Sarma, S. Das

doi:10.1103/physrevb.84.115301

Cited by 29 publications

(31 citation statements)

References 121 publications

(243 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The interaction energies are determined by the potential landscape realized to achieve this set {µ , δ i ,t ij ,Γ ij }, and comprise of the on-site Coulomb interaction terms U i and inter-site Coulomb interaction terms V ij . With each dot filled to an even number of electrons, we can describe the addition of the next two electrons per dot within an effective single-band extended Hubbard picture [33], using site-and-spin-specific electronic creation and annihilation operators c † iσ and c iσ and dot occupations n i = σ c † iσ c iσ :…”

Section: Methods and Resultsmentioning

confidence: 99%

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Hensgens

Fujita

Janssen

et al. 2017

Nature

Self Cite

326

329

View full text Add to dashboard Cite

Interacting fermions on a lattice can develop strong quantum correlations, which lie at the heart of the classical intractability of many exotic phases of matter [1, 2, 3, 4]. Seminal efforts are underway in the control of artificial quantum systems, that can be made to emulate the underlying Fermi-Hubbard models [5, 6, 7, 8,9,10,11]. Electrostatically confined conduction band electrons define interacting quantum coherent spin and charge degrees of freedom that allow all-electrical pure-state initialisation and readily adhere to an engineerable Fermi-Hubbard Hamiltonian [12,13,14,15,16,17,18,19,20,21,22,23]. Until now, however, the substantial electrostatic disorder inherent to solid state has made attempts at emulating Fermi-Hubbard physics on solid-state platforms few and far between [24,25]. Here, we show that for gate-defined quantum dots, this disorder can be suppressed in a controlled manner. Novel insights and a newly developed semi-automated and scalable toolbox allow us to homogeneously and independently dial in the electron filling and nearest-neighbour tunnel coupling. Bringing these ideas and tools to fruition, we realize the first detailed characterization of the collective Coulomb blockade transition [26], which is the finite-size analogue of the interaction-driven Mott metal-to-insulator transition [1]. As automation and device fabrication of semiconductor quantum dots continue to improve, the ideas presented here show how quantum dots can be used to investigate the physics of ever more complex many-body states.

show abstract

Section: Methods and Resultsmentioning

confidence: 99%

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Hensgens

Fujita

Janssen

et al. 2017

Nature

Self Cite

326

329

View full text Add to dashboard Cite

show abstract

“…1(a) is in accordance with previous CSDs calculated from a microscopic theory [32,33]. In contrast to these studies, in which only the doublewell potential is considered, we require that the DQD eigenstates are confined in a region of the size of the lithographics dimensions of the sample through W (r) in Eq.…”

Section: A Charge Stability Diagrammentioning

confidence: 85%

Controlled high-fidelity navigation in the charge stability diagram of a double quantum dot

Coden¹,

Romero²,

Räsänen³

2015

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We propose an efficient control protocol for charge transfer in a double quantum dot. We consider numerically a two-dimensional model system, where the quantum dots are subjected to timedependent electric fields corresponding to experimental gate voltages. Our protocol enables navigation in the charge stability diagram from a state to another through controllable variation of the fields. We show that the well-known adiabatic Landau-Zener transition -when supplemented with a time-dependent field tailored with optimal control theory -can remarkably improve the transition speed. The results also lead to a simple control scheme that requires only a single parameter obtained from the experimental charge stability diagram. Eventually, we can control the system at the fastest speed allowed by the quantum dynamics and with a high fidelity.

show abstract

“…Experiments are carried out at 100 mK temperatures, so thermal excitations may be neglected. Also, the effect of higher orbitals causes only a small renormalisation of the Hubbard parameters 33 . For these reasons, we retain only ground orbitals in our model.…”

Section: A Hamiltonianmentioning

confidence: 99%

Coherent transfer of singlet-triplet qubit states in an architecture of triple quantum dots

Feng¹,

Kwong

Koh³

et al. 2018

Phys. Rev. B

View full text Add to dashboard Cite

We propose two schemes to coherently transfer arbitrary quantum states of the two-electron singlet-triplet qubit across a chain of 3 quantum dots. The schemes are based on electrical control over the detuning energy of the quantum dots. The first is a pulse-gated scheme, requiring dc pulses and engineering of inter-and intra-dot Coulomb energies. The second scheme is based on the adiabatic theorem, requiring time-dependent control of the detuning energy through avoided crossings at a rate that the system remains in the ground state. We simulate the transfer fidelity using typical experimental parameters for silicon quantum dots. Our results give state transfer fidelities between 94.3% < F < 99.5% at sub-ns gate times for the pulse-gated scheme and between 75.4% < F < 99.0% at tens of ns for the adiabatic scheme. Taking into account dephasing from charge noise, we obtain state transfer fidelities between 94.0% < F < 99.2% for the pulse-gated scheme and between 64.9% < F < 93.6% for the adiabatic scheme. arXiv:1602.08596v2 [quant-ph]

show abstract

Quantum theory of the charge-stability diagram of semiconductor double-quantum-dot systems

Cited by 29 publications

References 121 publications

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Controlled high-fidelity navigation in the charge stability diagram of a double quantum dot

Coherent transfer of singlet-triplet qubit states in an architecture of triple quantum dots

Contact Info

Product

Resources

About