A quieter state of charge and ultra-low-noise of the collective current in quasi-1D charge-density-wave nanowires

Electronic flicker noise limits phase stability in communication systems, reduces the sensitivity and selectivity of sensors, and degrades coherence in quantum devices. There is a strong need for unconventional materials and strategies for achieving ultra-low-noise performance in nanoscale and quantum electronics. Here, we demonstrate that in nanowires of the quasi-one-dimensional, fully gapped charge-density-wave material (TaSe₄)₂I, low-frequency electronic noise is suppressed below the limit of thermalized charge carriers in passive resistors. When the current is dominated by the sliding Frohlich condensate, the normalized noise spectral density, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mrow><mml:mi>S</mml:mi></mml:mrow> <mml:mrow><mml:mi>I</mml:mi></mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:msup><mml:mrow><mml:mi>I</mml:mi></mml:mrow> <mml:mrow><mml:mn>2</mml:mn></mml:mrow> </mml:msup> </mml:math> , decreases linearly with current, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>I</mml:mi></mml:math> - a striking departure from the constant value of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mrow><mml:mi>S</mml:mi></mml:mrow> <mml:mrow><mml:mi>I</mml:mi></mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:msup><mml:mrow><mml:mi>I</mml:mi></mml:mrow> <mml:mrow><mml:mn>2</mml:mn></mml:mrow> </mml:msup> </mml:math> , observed in conventional conductors. No residual minimum noise level is reached for the current of the electron-lattice condensate in (TaSe₄)₂I nanowires. Repeating the measurements for another charge-density wave conductor, NbS₃-II, we found a similar reduction below the normal electron limit at room temperature. Our findings signal intrinsically lower current fluctuations within a correlated electron transport regime.