Credit: ETH Zurich/Chuyao Tong Researchers in the Laboratory for Solid State Physics at ETH Zurich discovered evidence that bilayer graphene quantum dots might host an appealing brand-new type of quantum bit based on so- called valley states.In quantum computing, the question as to what physical system, and which degrees of freedom within that system, might be utilized to encode quantum bits of info– qubits, in brief– is at the heart of lots of research projects brought out in physics and engineering laboratories. Rebekka Garreis, Dr. Chuyao Tong, Dr. Wister Huang and their colleagues in the group of Professors Klaus Ensslin and Thomas Ihn from the Department of Physics at ETH Zurich have been looking into bilayer graphene (BLG) quantum dots, understood as a potential platform for spin qubits, to discover out if another degree of freedom of BLG can be utilized to encode quantum information.Their most current findings, simply released on January 17 in Nature Physics with collaborators from the National Institute for Materials Science in Japan, reveal that the so-called valley degree of flexibility in BLG is associated with quantum states that are incredibly long-lived and are therefore worth considering even more as an additional resource for solid-state quantum computing.The Strength of Graphene LayersGraphene is a two-dimensional material given by a single layer of carbon atoms bound in a hexagonal lattice structure. For this reason, they are an important platform for spin qubits, systems where quantum information is encoded in the electron spin degree of freedom.Because quantum information is much more prone to being damaged– and therefore end up being inappropriate for computational jobs– by the surrounding environment than its classical equivalent, scientists who study various qubit candidates need to define their coherence residential or commercial properties: these tell them how well and for how long quantum info can endure in their qubit system.In most standard quantum dots, electron spin decoherence can be caused by the spin-orbit interaction, which presents an undesirable coupling in between the electron spin and the vibrations of the host lattice, and the hyperfine interaction between the electron spin and the surrounding nuclear spins.In graphene as well as in other carbon-based materials, spin-orbit coupling and hyperfine interaction are both weak: this makes graphene quantum dots particularly appealing for spin qubits.
Credit: ETH Zurich/Chuyao Tong Researchers in the Laboratory for Solid State Physics at ETH Zurich discovered proof that bilayer graphene quantum dots might host an appealing new type of quantum bit based on so- called valley states.In quantum computing, the question as to what physical system, and which degrees of freedom within that system, might be utilized to encode quantum bits of information– qubits, in brief– is at the heart of numerous research jobs brought out in physics and engineering laboratories. Rebekka Garreis, Dr. Chuyao Tong, Dr. Wister Huang and their coworkers in the group of Professors Klaus Ensslin and Thomas Ihn from the Department of Physics at ETH Zurich have actually been looking into bilayer graphene (BLG) quantum dots, known as a possible platform for spin qubits, to discover out if another degree of flexibility of BLG can be utilized to encode quantum information.Their latest findings, simply published on January 17 in Nature Physics with partners from the National Institute for Materials Science in Japan, reveal that the so-called valley degree of liberty in BLG is associated with quantum states that are very long-lived and are therefore worth thinking about even more as an extra resource for solid-state quantum computing.The Strength of Graphene LayersGraphene is a two-dimensional material given by a single layer of carbon atoms bound in a hexagonal lattice structure. For this factor, they are an important platform for spin qubits, systems where quantum details is encoded in the electron spin degree of freedom.Because quantum details is much more susceptible to being damaged– and for that reason end up being inappropriate for computational tasks– by the surrounding environment than its classical counterpart, scientists who study various qubit candidates must identify their coherence properties: these inform them how well and for how long quantum details can endure in their qubit system.In most traditional quantum dots, electron spin decoherence can be caused by the spin-orbit interaction, which introduces an unwanted coupling between the electron spin and the vibrations of the host lattice, and the hyperfine interaction in between the electron spin and the surrounding nuclear spins.In graphene as well as in other carbon-based products, spin-orbit coupling and hyperfine interaction are both weak: this makes graphene quantum dots particularly appealing for spin qubits. The findings presented by Garreis, Tong, and partners make the case for including valley states in BLG quantum dots to the landscape of solid-state quantum computing.Reference: “Long-lived valley states in bilayer graphene quantum dots” by Rebekka Garreis, Chuyao Tong, Jocelyn Terle, Max Josef Ruckriegel, Jonas Daniel Gerber, Lisa Maria Gächter, Kenji Watanabe, Takashi Taniguchi, Thomas Ihn, Klaus Ensslin and Wei Wister Huang, 17 January 2024, Nature Physics.DOI: 10.1038/ s41567-023-02334-7.