18:15 〜 18:30
▲ [23p-E205-18] Decoherence Noise Spectroscopy of CaF2 and NaCl using Multiple-Pulse Sequence
キーワード：Spin qubit, Noise spectroscopy, Dynamical decoupling
Dynamical decoupling using multiple-pulse sequences has been known as a method to protect quantum bits (qubits) from a noisy environment, leading to the enhancement of coherence time. The sequences are also useful as a spectrometer to characterize environmental noises near spin qubits.
So far as the noise on nuclear spins is concerned, however, there has been a discrepancy in the frequency dependences. To resolve such issues, we have proposed a consistent method to obtain the spectrum of decoherence noise on nuclear spins both theoretically and experimentally. In the previous theory, we have clarified that the spectral intensity must be defined as the long-time limit of multiple spin-echo decays under multiple inversion pulses. This definition enables us to avoid experimental artifacts generally observed in the initial behavior of the multiple spin-echo intensities. Indeed, we have shown that this definition results in reasonable findings on the frequency spectra of the decoherence noise in GaAs.
In this meeting, we present the spectra of decoherence noises on nuclear spins in solid crystals of CaF2 and NaCl. In the study, we employ a phase-inverted multiple-π-pulse sequence, known as alternating phase Carr-Purcell (APCP). As a result, we have found that -dependence gives the best fit to both of these. Based on these results, we also discuss the origin of the decoherence noise on both cases.
So far as the noise on nuclear spins is concerned, however, there has been a discrepancy in the frequency dependences. To resolve such issues, we have proposed a consistent method to obtain the spectrum of decoherence noise on nuclear spins both theoretically and experimentally. In the previous theory, we have clarified that the spectral intensity must be defined as the long-time limit of multiple spin-echo decays under multiple inversion pulses. This definition enables us to avoid experimental artifacts generally observed in the initial behavior of the multiple spin-echo intensities. Indeed, we have shown that this definition results in reasonable findings on the frequency spectra of the decoherence noise in GaAs.
In this meeting, we present the spectra of decoherence noises on nuclear spins in solid crystals of CaF2 and NaCl. In the study, we employ a phase-inverted multiple-π-pulse sequence, known as alternating phase Carr-Purcell (APCP). As a result, we have found that -dependence gives the best fit to both of these. Based on these results, we also discuss the origin of the decoherence noise on both cases.