Circular THz ratchets in a 2D-modulated Dirac system
Abstract: We report on the observation of the circular ratchet effect excited by terahertz laser radiation in a specially designed two-dimensional metamaterial consisting of a graphene monolayer deposited on a graphite gate patterned with an array of triangular antidots. We show that a periodically driven Dirac fermion system with spatial asymmetry converts the a.c. power into a d.c. current, whose direction reverses when the radiation helicity is switched. The circular ratchet effect is demonstrated for room temperature and a radiation frequency of 2.54 THz. It is shown that the ratchet current magnitude can be controllably tuned by the patterned and uniform back gate voltages. The results are analyzed in the light of the developed microscopic theory considering electronic and plasmonic mechanisms of the ratchet current formation.
- T. Otsuji, Trends in the research of modern terahertz detectors: Plasmon detectors, IEEE Transactions on Terahertz Science and Technology 5, 1110 (2015).
- A. Rogalski, M. Kopytko, and P. Martyniuk, Two-dimensional infrared and terahertz detectors: Outlook and status, Appl. Phys. Rev. 6, 021316 (2019).
- R. A. Lewis, A review of terahertz detectors, Journal of Physics D: Applied Physics 52, 433001 (2019).
- Y. Y. Kiselev and L. E. Golub, Optical and photogalvanic properties of graphene superlattices formed by periodic strain, Phys. Rev. B 84, 235440 (2011).
- A. V. Nalitov, L. E. Golub, and E. L. Ivchenko, Ratchet effects in two-dimensional systems with a lateral periodic potential, Phys. Rev. B 86, 115301 (2012).
- G. V. Budkin and L. E. Golub, Orbital magnetic ratchet effect, Phys. Rev. B 90, 125316 (2014).
- V. V. Popov, Polarization-dependent plasmonic photocurrents in two-dimensional electron systems, Appl. Phys. Lett. 108, 261104 (2016).
- E. L. Ivchenko and S. D. Ganichev, Ratchet effects in quantum wells with a lateral superlattice, JETP Lett. 93, 673 (2011), [Pisma v ZhETF 93, 752 (2011)].
- I. Rozhansky, V. Kachorovskii, and M. Shur, Helicity-driven ratchet effect enhanced by plasmons, Phys. Rev. Lett. 114, 246601 (2015).
- K. Romanov and M. Dyakonov, Theory of helicity-sensitive terahertz radiation detection by field effect transistors, Applied Physics Letters 102 (2013).
- I. V. Gorbenko, V. Y. Kachorovskii, and M. S. Shur, Plasmonic helicity-driven detector of terahertz radiation, physica status solidi (RRL) – Rapid Research Letters 13, 10.1002/pssr.201800464 (2018).
- S. D. Ganichev, Tunnel ionization of deep impurities in semiconductors induced by terahertz electric fields, Phys. B 273-274, 737 (1999).
- M. M. Glazov and S. D. Ganichev, High frequency electric field induced nonlinear effects in graphene, Phys. Rep. 535, 101 (2014).
- S. D. Ganichev, D. Weiss, and J. Eroms, Terahertz electric field driven electric currents and ratchet effects in graphene, Ann. Phys. 529, 1600406 (2017).
- It is usually realized in small-sized graphene samples.
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