Coherence times and Rabi oscillations in CaWO₄:Cr⁵⁺ crystal

详细信息    查看全文

• 作者：Eduard Baibekov^a ; ^{edbaibek@gmail.com} ; Igor Kurkin^a ; Marat Gafurov^a ; ^b ; Burkhard Endeward^b ; Rafail Rakhmatullin^a ; Georgy Mamin^a
• 关键词：Pulsed ESR ; Calcium tungstate ; Pentavalent chromium ; Rabi oscillations ; Inhomogeneous fields
• 刊名：Journal of Magnetic Resonance
• 出版年：2011
• 出版时间：March 2011
• 年：2011
• 卷：209
• 期：1
• 页码：61-68
• 全文大小：899 K

文摘

The coherence times of dopant pentavalent chromium ions in CaWO₄ single crystal (0.0006 at. % Cr⁵⁺) were investigated both theoretically and experimentally. Temperature dependences of spin–lattice relaxation time T₁ and phase memory time T_M were measured in the temperature range 6–30 K at high (94 GHz, W band) and low (3.5 GHz, S band) frequencies of electron spin resonance. It follows from T_M calculations that phase relaxation of Cr⁵⁺ ion arises mainly from magnetic dipole interactions between the chromium ions.

Anomalously fast damping of Rabi oscillations is detected in both S- and W-band experiments. It is shown that this phenomenon is caused by microwave field inhomogeneity inside the resonator. Relations between the damping time of Rabi oscillations, Rabi frequency and the crystal sample size are obtained. Lumped-element resonators and smaller sample dimensions are suggested to lower spin dephasing during transient nutations.