Multielectron dots provide faster Rabi oscillations when the core
electrons are strongly confined
- URL: http://arxiv.org/abs/2303.02958v1
- Date: Mon, 6 Mar 2023 08:11:16 GMT
- Title: Multielectron dots provide faster Rabi oscillations when the core
electrons are strongly confined
- Authors: H. Ekmel Ercan, Christopher R. Anderson, S. N. Coppersmith, Mark
Friesen, Mark F. Gyure
- Abstract summary: We study one- and three-electron quantum dots in silicon/silicon-germanium heterostructures.
Our calculations show that anharmonicity of the confinement potential plays an important role.
These findings have important implications for the design of multielectron Si/SiGe quantum dot qubits.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Increasing the number of electrons in electrostatically confined quantum dots
can enable faster qubit gates. Although this has been experimentally
demonstrated, a detailed quantitative understanding has been missing. Here we
study one- and three-electron quantum dots in silicon/silicon-germanium
heterostructures within the context of electrically-driven spin resonance
(EDSR) using full configuration interaction and tight binding approaches. Our
calculations show that anharmonicity of the confinement potential plays an
important role: while the EDSR Rabi frequency of electrons in a harmonic
potential is indifferent to the electron number, soft anharmonic confinements
lead to larger and hard anharmonic confinements lead to smaller Rabi
frequencies. We also confirm that double dots allow fast Rabi oscillations, and
further suggest that purposefully engineered confinements can also yield
similarly fast Rabi oscillations in a single dot. Finally, we discuss the role
of interface steps. These findings have important implications for the design
of multielectron Si/SiGe quantum dot qubits.
Related papers
- Measurement of enhanced spin-orbit coupling strength for donor-bound electron spins in silicon [0.0]
We show that the strength of the spin-orbit coupling can be locally enhanced by more than two orders of magnitude in the manybody wave functions of multi-donor quantum dots compared to a single donor.
Our findings may provide a pathway towards all-electrical control of donor-bound spins in silicon using electric dipole spin resonance (EDSR)
arXiv Detail & Related papers (2024-04-24T09:34:56Z) - Impact of electrostatic crosstalk on spin qubits in dense CMOS quantum
dot arrays [0.2529650288460727]
Current CMOS spin qubit processors consist of dense gate arrays to define the quantum dots.
Small but sizeable spin-orbit interactions can transfer this electrostatic crosstalk to the spin g-factors.
By studying the Stark shift from tens of spin qubits measured in nine different CMOS devices, we developed a theoretical frawework that explains how electric fields couple to the spin of the electrons.
arXiv Detail & Related papers (2023-09-04T22:44:24Z) - Jellybean quantum dots in silicon for qubit coupling and on-chip quantum
chemistry [0.6818394664182874]
Small size and excellent integrability of silicon metal-oxide-semiconductor (SiMOS) quantum dot spin qubits make them an attractive system for mass-manufacturable, scaled-up quantum processors.
This paper investigates the charge and spin characteristics of an elongated quantum dot for the prospects of acting as a qubit-qubit coupler.
arXiv Detail & Related papers (2022-08-08T12:24:46Z) - Enhancing the Coherence of Superconducting Quantum Bits with Electric
Fields [62.997667081978825]
We show that qubit coherence can be improved by tuning defects away from the qubit resonance using an applied DC-electric field.
We also discuss how local gate electrodes can be implemented in superconducting quantum processors to enable simultaneous in-situ coherence optimization of individual qubits.
arXiv Detail & Related papers (2022-08-02T16:18:30Z) - On-demand electrical control of spin qubits [0.49813399226871663]
We demonstrate a technique that enables a emphswitchable interaction between spins and orbital motion of electrons in silicon quantum dots.
The naturally weak effects of the relativistic spin-orbit interaction in silicon are enhanced by more than three orders of magnitude by controlling the energy quantisation of electrons in the nanostructure.
arXiv Detail & Related papers (2022-01-18T00:43:54Z) - Strong electron-electron interactions in Si/SiGe quantum dots [0.0]
We study two-electron wavefunctions in electrostatically confined quantum dots formed in a SiGe/Si/SiGe quantum well at zero magnetic field.
Our calculations show that strong electron-electron interactions, induced by weak confinement, can significantly suppress the low-lying, singlet-triplet excitation energy.
These results have important implications for the rational design and fabrication of quantum dot qubits with predictable properties.
arXiv Detail & Related papers (2021-05-22T06:12:39Z) - Controlled coherent dynamics of [VO(TPP)], a prototype molecular nuclear
qudit with an electronic ancilla [50.002949299918136]
We show that [VO(TPP)] (vanadyl tetraphenylporphyrinate) is a promising system suitable to implement quantum computation algorithms.
It embeds an electronic spin 1/2 coupled through hyperfine interaction to a nuclear spin 7/2, both characterized by remarkable coherence.
arXiv Detail & Related papers (2021-03-15T21:38:41Z) - Fast high-fidelity single-qubit gates for flip-flop qubits in silicon [68.8204255655161]
flip-flop qubit is encoded in the states with antiparallel donor-bound electron and donor nuclear spins in silicon.
We study the multilevel system that is formed by the interacting electron and nuclear spins.
We propose an optimal control scheme that produces fast and robust single-qubit gates in the presence of low-frequency noise.
arXiv Detail & Related papers (2021-01-27T18:37:30Z) - Electrically tuned hyperfine spectrum in neutral
Tb(II)(Cp$^{\rm{iPr5}}$)$_2$ single-molecule magnet [64.10537606150362]
Both molecular electronic and nuclear spin levels can be used as qubits.
In solid state systems with dopants, an electric field was shown to effectively change the spacing between the nuclear spin qubit levels.
This hyperfine Stark effect may be useful for applications of molecular nuclear spins for quantum computing.
arXiv Detail & Related papers (2020-07-31T01:48:57Z) - Quantum coherent spin-electric control in a molecular nanomagnet at
clock transitions [57.50861918173065]
Electrical control of spins at the nanoscale offers architectural advantages in spintronics.
Recent demonstrations of electric-field (E-field) sensitivities in molecular spin materials are tantalising.
E-field sensitivities reported so far are rather weak, prompting the question of how to design molecules with stronger spin-electric couplings.
arXiv Detail & Related papers (2020-05-03T09:27:31Z) - Entanglement generation via power-of-SWAP operations between dynamic
electron-spin qubits [62.997667081978825]
Surface acoustic waves (SAWs) can create moving quantum dots in piezoelectric materials.
We show how electron-spin qubits located on dynamic quantum dots can be entangled.
arXiv Detail & Related papers (2020-01-15T19:00:01Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.