Reliability and Operation Cost of Underdamped Memories during Cyclic Erasures

Abstract

Abstract The reliability of fast repeated erasures is studied experimentally and theoretically in a 1‐bit underdamped memory. The bit is encoded by the position of a micro‐mechanical oscillator whose motion is confined in a double well potential. To contain the energetic cost of fast erasures, a resonator with high quality factor Q is used: the erasure work W is close to Landauer's bound, even at high speed. The drawback is the rise of the system's temperature T due to a weak coupling to the environment. Repeated erasures without letting the memory thermalize between operations result in continuous warming, potentially leading to a thermal noise overcoming the barrier between the potential wells. In such a case, the reset operation can fail to reach the targeted logical state. The reliability is characterized by the success rate Ris after i successive operations. W, T, and Ris are studied experimentally as a function of the erasure speed. Above a velocity threshold, T soars while Ris collapses: the reliability of too‐fast erasures is low. These experimental results are fully justified by two complementary models. It is demonstrated that Q ≃ 10 is optimal to contain energetic costs and maintain high‐reliability standards for repeated erasures at any speed.

Keywords

• adiabatic erasure
• information erasure
• Landauer's bound
• stochastics thermodynamics
• underdamped memory