Rare earth ions doped mixed crystals for fast quantum computers with optical frequency qubits

OPTICS COMMUNICATIONS

卷:485

Article

Hizhnyakov, Vladimir¹  Boltrushko, Vadim¹  Kaasik, Helle¹  Orlovskii, Yurii^1,2 

[1] Univ Tartu, Inst Phys, 1 W Ostwald St, EE-50411 Tartu, Estonia

[2] Prokhorov Gen Phys Inst RAS, 38 Vavilov St, Moscow 119991, Russia

关键词: Quantum computers;    Qubits;    Quantum CNOT gate;    Rare-earth ions;    Mixed crystals;    quadrupole-quadrupole interaction;    Stark blockade;    Judd-Ofelt theory;   

DOI  :  10.1016/j.optcom.2020.126693

来源: Elsevier

【 摘 要 】

The possibility of using mixed crystals highly doped with rare earth ions (REIs) as physical systems for creating fast quantum computers with a sampling time of 10(-9) s is discussed. The electronic (4)f states of rare earth ions with small values of the diagonal elements of the Judd-Ofelt matrix U-(2) are proposed as optical frequency qubit levels. CNOT and other conditional gate operations are performed by exciting the rare earth ion into the (4)f state with a large diagonal element of U-(2), causing a Stark blockade. It is found that the main interaction responsible for this blockade is the quadrupole-quadrupole interaction. The large inhomogeneous broadening of the frequencies of the electronic transitions in mixed crystals and the weak interaction of (4)f electrons with phonons make it possible to achieve a high computation rate and a long decoherence time of the qubits. An ensemble of closest REIs is described that can act as an OQC instance; the frequencies of the corresponding qubits can be found using the spectral hole burning method.

【 授权许可】

Free