We present a quantum switch based on analogous Dirac fermion optics (DFO), in which the angle dependence of Klein tunneling is explicitly utilized to build tunable collimators and reflectors for the quantum wave function of Dirac fermions. We employ a dual-source design with a single flat reflector, which minimizes diffusive edge scattering and suppresses the background incoherent transmission. Our gate-tunable collimator–reflector device design enables the quantitative measurement of the net DFO contribution in the switching device operation. We obtain a full set of transmission coefficients between multiple leads of the device, separating the classical contribution from the coherent transport contribution. The DFO behavior demonstrated in this work requires no explicit energy gap. We demonstrate its robustness against thermal fluctuations up to 230 K and large bias current density up to 10 2 A/m, over a wide range of carrier densities. The characterizable and tunable optical components (collimator–reflector) coupled with the conjugated source electrodes developed in this work provide essential building blocks toward more advanced DFO circuits such as quantum interferometers. The capability of building optical circuit analogies at a microscopic scale with highly tunable electron wavelength paves a path toward highly integrated and electrically tunable electron-optical components and circuits.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Apr 2 2019|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS. The experimental work and theoretical analysis were partly supported by INDEX, a funded center of Nanoelectronics Research Initiative, a Semiconductor Research Corporation program sponsored by Nanoelectronics Research Corporation and National Institute of Standards and Technology. P.K. acknowledges support from Office of Naval Research (ONR) Award N00014-16-1-2921 and the Lloyd Foundation. K. Wang acknowledges partial support from ONR Award N00014-15-1-2761. G.-H.L. acknowledges partial support from the National Research Foundation of Korea Grant funded by the Korean Government (Grant 2016R1A5A1008184). K. Watanabe and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the Ministry of Education, Culture, Sports, Science and Technology, Japan, and Creating the Seeds for New Technology (Award JPMJCR15F3), Japan Science and Technology Agency.
© 2019 National Academy of Sciences. All Rights Reserved.
- Dirac fermion
- Electron optics
- Quantum transport