Spin qubits in graphene quantum dots

By B. Trauzettel, D. V. Bulaev, Daniel Loss, G. Burkard. 2006

921 citations recorded by the source corpus.

The main characteristics of good qubits are long coherence times in combination with fast operating times. It is well known that carbon-based materials could increase the coherence times of spin qubits, which are among the most developed solid-state qubits. Here, we propose how to form spin qubits in graphene quantum dots. A crucial requirement to achieve this goal is to find quantum-dot states where the usual valley degeneracy in bulk graphene is lifted. We show that this problem can be avoided in quantum dots based on ribbons of graphene with armchair boundaries. The most remarkable new feature of the proposed spin qubits is that, in an array of many qubits, it is possible to couple any two of them via Heisenberg exchange with the others being decoupled by detuning. This unique feature is a direct consequence of the quasi-relativistic spectrum of graphene.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/a1c3ba2ae5dd5a3c42016023991d9a2027e87ef4

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In Atomic and Molecular Physics, and Optics

In Electrical and Electronic Engineering

In Materials Chemistry

Citations in the corpus

A quantum spin transducer based on nanoelectromechanical resonator arrays (2009, background): “However, such channels are absent for many spin qubits including prominen t examples such as phosphor donors in silicon [10, 11, 12, 13] or N@C 60 [14, 15, 16], as well as new generations of carbon [17, 18], and silicon [19, 20] based quantum dots.”
Graphene and derivatives – Synthesis techniques, properties and their energy applications (2017, positive): “Out of all the reducing agents hydrazine hydride was referred as the best reducing agent to produce very thin graphene sheets, additionally, it does not react with water.”
Substrate-induced bandgap opening in epitaxial graphene. (2007, background): “To induce these perturbations, various graphene super-structures, such as graphene quantum dots [6], graphene ribbons [7–10], and devices based on the combination of single and bilayer graphene regions [11, 13, 14] have been proposed.”
Emergence of magnetism in graphene materials and nanostructures (2010, background): “Materials based on light elements also display weak spin-orbit and hyperfine couplings which are the main channels of relaxation and decoherence of electron spins (Fischer et al., 2009; Trauzettel et al., 2007; Yazyev, 2008a).”
Manipulating the electronic and chemical properties of graphene via molecular functionalization (2013, background): “Various graphene nanostructures have been fabricated to open a bandgap up to a few hundred meV, such as graphene quantum dots [88,89], graphene nanoribbons [90–92] and nanomesh [93,94].”