Radio Frequency Tunable Oscillator Device Based on SmB6 Microcrystal

Abstract

Radio frequency tunable oscillators are vital electronic components for signal generation, characterization, and processing. They are often constructed with a resonant circuit and a 'negative' resistor, such as a Gunn-diode, involving complex structure and large footprints. Here we report that a piece of SmB6, 100 micron in size, works as a current-controlled oscillator in the 30 MHz frequency range. SmB6 is a strongly correlated Kondo insulator that was recently found to have a robust surface state likely to be protected by the topology of its electronics structure. We exploit its non-linear dynamics, and demonstrate large AC voltage outputs with frequencies from 20 Hz to 30 MHz by adjusting a small DC bias current. The behaviors of these oscillators agree well with a theoretical model describing the thermal and electronic dynamics of coupled surface and bulk states. With reduced crystal size we anticipate the device to work at higher frequencies, even in the THz regime. This type of oscillator might be realized in other materials with a metallic surface and a semiconducting bulk.

v3 to appear in Physical Review Letters

References in corpus (8)

• Topological Kondo Insulators
• Unconventional Fermi surface in an insulating state
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Tuning bulk and surface conduction in topological Kondo insulator SmB6
• Kondo Breakdown in Topological Kondo Insulators
• Two-dimensional heavy fermions on the strongly correlated boundaries of Kondo topological insulators
• A Strongly-Interacting Dirac Liquid on the Surface of a Topological Kondo Insulator
• Many-Body Effects in Topological Kondo Insulators

Cited by in corpus (7)

• Kondo insulator SmB6 under strain: surface dominated conduction near room temperature
• Surface and electronic structure of SmB${}_6$ through Scanning Tunneling Microscopy
• Ultra-low Power Microwave Oscillators based on Phase Change Oxides as Solid-State Neurons
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Realizing a topological diode effect on the surface of a topological Kondo insulator
• Direct observation of surface state thermal oscillation in SmB6 oscillators
• Slow crystalline electric field fluctuations in the Kondo lattice SmB${}_6$