Stochastic antiresonance in qubit phase estimation with quantum thermal noise

Stochastic Resonance with Unital Quantum Noise

“…Forms of stochastic resonance have been investigated for information communication over qubit channels [21][22][23][24]. For quantum sensors and metrology, stochastic resonance has recently been extended to situations of quantum state detection [25] or quantum state estimation [26,27] from noisy qubits. These forms of stochastic resonance in [25][26][27] have been shown possible speci¯cally with quantum thermal noise acting on the qubit, where the decohering environment is represented as a thermal bath at¯nite temperature.…”

“…For quantum sensors and metrology, stochastic resonance has recently been extended to situations of quantum state detection [25] or quantum state estimation [26,27] from noisy qubits. These forms of stochastic resonance in [25][26][27] have been shown possible speci¯cally with quantum thermal noise acting on the qubit, where the decohering environment is represented as a thermal bath at¯nite temperature. Regimes were reported in [25][26][27], where an increase in the noise temperature can prove favorable to the metrological performance from the noisy qubit, in quantum detection or estimation.…”

“…These forms of stochastic resonance in [25][26][27] have been shown possible speci¯cally with quantum thermal noise acting on the qubit, where the decohering environment is represented as a thermal bath at¯nite temperature. Regimes were reported in [25][26][27], where an increase in the noise temperature can prove favorable to the metrological performance from the noisy qubit, in quantum detection or estimation. The quantum thermal noise, as we shall explain below, owns the important property of being a non-unital quantum noise, exhibiting in some sense a lesser degree of symmetry, and this non-unital character is essential to the forms of stochastic resonance observed in [25][26][27].…”

“…Regimes were reported in [25][26][27], where an increase in the noise temperature can prove favorable to the metrological performance from the noisy qubit, in quantum detection or estimation. The quantum thermal noise, as we shall explain below, owns the important property of being a non-unital quantum noise, exhibiting in some sense a lesser degree of symmetry, and this non-unital character is essential to the forms of stochastic resonance observed in [25][26][27]. There however exist other important quantum noises acting on the qubit that are unital noises, exhibiting higher degree of symmetry.…”

“…The class of unital quantum noises contains many important noises for the qubit, such as the bit-°ip, the phase-°ip, the depolarizing noises, or the whole family of Pauli noises. The forms of stochastic resonance reported in [25][26][27] were not investigated in the presence of such common unital noises for the qubit. So far, no scenario has been reported in quantum metrology, detection or estimation, showing the possibility of stochastic resonance e®ects with such unital quantum noises, and it is not known whether this is possible or not.…”