Speaker
Description
We present a theoretical investigation of back-action noise cancellation in a hybrid optomechanical cavity system, equipped with a quantum well (QW) [1] and supplemented with an optical parametric amplifier (OPA). In conventional optomechanical systems, quantum back-action noise arising from radiation-pressure fluctuations imposes the standard quantum limit (SQL) on force sensitivity [2,3], thereby restricting the detection of extremely weak forces. In our hybrid model, the exciton–photon interaction between the quantum well and the cavity field modifies the system response, opening auxiliary interference channels that can be exploited for noise suppression. By employing the scheme of coherent quantum noise cancellation (CQNC) [3,4], we establish the conditions under which destructive interference between the back-action force and the QW-induced auxiliary noise pathways results in complete elimination of measurement back-action. In addition, the inclusion of the OPA introduces a controllable nonlinearity into the cavity, which provides an effective means to reduce shot noise and enhance the tunability of the overall system dynamics. By gradually increasing the OPA pump gain, we demonstrate that back-action cancellation can be achieved at reduced driving laser power, while simultaneously enhancing the sensitivity of weak force detection [5]. This combined effect enables SQL-beating performance under realistic operating conditions. Our analysis, carried out within the Langevin equation framework, shows that appropriate tuning of the couplings and OPA gain allows the system to transition from SQL-limited operation to a back-action–free regime. These findings establish QW–cavity–optomechanical hybrid system as a promising platform for next-generation quantum sensing, precision metrology, and weak force detection beyond the reach of conventional back-action–limited systems.
