Research

Research topics

Quantum transport in semiconducting nanostructures

- 3D Dirac semimetal nanowires and nano-plates

- InAs nanowires

- Selectively grown InAs nanowires

- 2D van der Waals materials

High frequency measurements in quantum nanodevices

- Quantum dots coupled to superconducting microwave circuits

- Charge pumping devices

- Shot noise measurements in quantum dots using impedance matching circuits

- Cavity spintronics

Recent scientific achievements

Quantum dots coupled to microwave circuits

We demonstrated sensing spin-orbit qubits in InAs nanowire single and double quantum dots with RF reflectometry.^1-3 We also performed shot noise measurements with superconducting microwave matching circuits which can probe information about electron transmission in nano-devices.^4-7 By using microwave matching circuits, we improved a detection limit of shot noise by a few orders of magnitude than that of low frequency measurements.

Quantum dot formation in 3D Dirac semimetal nanowires

We demonstrated quantum dot formation in 3D Dirac semimetal nanowires by suppression the Klein tunneling with magnetic fields for the first time.⁸ Dirac semimetals are a 3D analogue of graphene so that it is not feasible to confine carriers with p-n junctions due to the Klein tunneling. However, we formed a n-p-n junction with gate and source-drain contacts and applied high magnetic fields to suppress the Klein tunneling at the p-n junction. We observed clean Coulomb diamond features at high magnetic fields, indicating that a clean single quantum dot is formed in 3D Dirac semimetal nanowires.

References

1. M. Jung, M. D. Schroer, K. D. Petersson, and J. R. Petta, Appl. Phys. Lett. 100, 253508 (2012).

2. M. D. Schroer, M. Jung, K. D. Petersson, and J. R. Petta, Phys. Rev. Lett.109, 166804 (2012).

3. K. D. Petersson, L. W. McFaul, M. D. Schroer, M. Jung, J. M. Taylor, A. A. Houck and J. R. Petta, Nature 490, 380 (2012).

4. M. Jung, J. Schindele, S. Nau, M. Weiss, A. Baumgartner and C. Schönenberger, Nano Lett. 13, 4522 (2013).

5. V. Ranjan, G. Puebla-Hellmann, M. Jung, T. Hasler, A. Nunnenkamp, M. Muoth, C. Hierold, A. Wallraff, and C. Schönenberger, Nature commun. 6, 7165 (2015).

6. T. Hasler, M. Jung, V. Ranjan, G. Puebla-Hellmann, A. Wallraff, and C. Schönenberger, Phys. Rev. Applied. 4, 054002 (2015).

7. M. -C. Harabula, T. Hasler, G. Fülöp, M. Jung, V. Ranjan, and C. Schönenberger, Phys. Rev. Appl. 8, 54006 (2017).

8. M. Jung, K. Yoshida, K. Park, X.-X. Zhang, C. Yesilyurt, Z. B. Siu, M. B. A. Jalil, J. Park, J. Park, N. Nagaosa, J. Seo, and K. Hirakawa, Nano Lett. 18, 1863 (2018).