Dynamically dual-tunable dual-band to four-band metamaterial absorbers based on bulk Dirac semimetal and vanadium dioxide
BaoJing Hu, Ming Huang, Peng Li, JingJing Yang
Abstract
In this work, we investigate dynamically dual-tunable dual-band, triple-band, and four-band metamaterial absorbers (MAs) based on a bulk Dirac semimetal (BDS) and vanadium dioxide ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">V</mml:mi> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ). Due to the bright-bright mode coupling between BDS rods, the dual-band, triple-band, and four-band MAs can be realized when the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">V</mml:mi> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> is in a fully metallic state. The average absorptivity of the absorption peaks in the three MAs reaches 97%, 98.6%, and 96.4% respectively. The physical mechanism can be explained by the radiating two-oscillator model. The resonant frequencies and absorptance intensities at absorption peaks in each MA can be dynamically tuned by varying the BDS Fermi energy and the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">V</mml:mi> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> conductivity.