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QUANTUM COMPUTING

2D materials shrink superconducting qubits

Nature Materials volume 21, pages 381–382 (2022)Cite this article

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The exceptional quality of hexagonal boron nitride crystals that can be cleaved into few layers provides ultrathin dielectrics, thereby opening a route to ultrasmall capacitors with large capacitances. With such capacitors, the superconducting transmon qubit is scaled down by orders of magnitude.

We are in the midst of the race towards a quantum computer that can solve ‘computationally hard’ problems1. At present, the most advanced solid-state-based implementations make use of superconducting circuits2. Superconductors have the amazing property of coherent macroscopic quantum states, promising low dissipation and, consequently, long coherence times. The most advanced quantum bit, based on superconductivity, is the transmon qubit3. It consists in essence of a Josephson junction shunted by a large capacitor with capacitance C. As a Josephson junction is an inductor with a flux-controlled inductance L, this circuit makes up an LC-oscillator with frequency \(f=1/2\pi \sqrt{LC}\). The two qubit states are the ground state and the first excited state of the oscillator. Although we can praise superconductors as being lossless conductors, the coherence of an arbitrary qubit state, which is a superposition of the ground state and the excited state, is still lost after some time owing to various couplings to uncontrolled environmental degree of freedoms. There is a finite density of quasiparticles that generate loss, there is noise in the readout and drive circuitries, and there is charge and flux noise owing to defect states in dielectrics and magnetic impurities.

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Fig. 1: The Xmon qubit.

References

  1. Autre, F. et al. Nature 574, 505–510 (2019).

    Article  Google Scholar 

  2. Krantz, P. Appl. Phys. Rev. 6, 021318 (2019).

    Article  Google Scholar 

  3. Koch, J. Phys. Rev. A 76, 042319 (2007).

    Article  Google Scholar 

  4. Nakamura, Y., Pashkin, P. A. & Tsai, J. S. Nature 398, 786–788 (1999).

    Article  CAS  Google Scholar 

  5. Barends, R. et al. Phys. Rev. Lett. 111, 080502 (2013).

    Article  CAS  Google Scholar 

  6. Wang, J. I.-J. et al. Nat. Mater. https://doi.org/10.1038/s41563-021-01187-w (2022).

    Article  Google Scholar 

  7. Antony, A. et al. Nano Lett. 21, 10122 (2021).

    Article  CAS  Google Scholar 

  8. Geim, A. K. & Grigorieva, I. V. Nature 499, 419–425 (2013).

    Article  CAS  Google Scholar 

  9. Dean, C. R. et al. Nat. Nanotechnol. 5, 722–726 (2010).

    Article  CAS  Google Scholar 

  10. Zastrow, M. Nature 572, 429–432 (2019).

    Article  CAS  Google Scholar 

Download references

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  1. Nanoelectronics Group, Department of Physics, University of Basel, Basel, Switzerland

    Christian Schönenberger

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  1. Christian Schönenberger
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Correspondence to Christian Schönenberger.

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Schönenberger, C. 2D materials shrink superconducting qubits. Nat. Mater. 21, 381–382 (2022). https://doi.org/10.1038/s41563-022-01220-6

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