In the field of quantum computation, one of the key issues is how to prolong the decoherence time of qubits. In the present work, the decoherence time is calculated in the framework of the Landau-Pekar variational approach for an anisotropic quantum dot (QD) under external electric fields including electron–phonon interactions. We obtained the parameterized eigenenergies of the ground state (GS) and the first excited-state (ES) by constructing the electronic wave functions for the GS and the first ES. We demonstrate that the calculation can explain consistently the dependence of decoherence time on the electric field strength, longitudinal-optical phonons and impurities. Our results should be useful for experimental investigation of QD qubit.

在量子计算领域，关键问题之一是如何延长量子位的去相干时间。在当前的工作中，在包括电子-声子相互作用的外部电场下，各向异性各向异性量子点（QD）的Landau-Pekar变分方法框架中计算了退相干时间。通过构造GS和第一个ES的电子波函数，我们获得了基态（GS）和第一激发态（ES）的参数化本能。我们证明了该计算可以一致地解释退相干时间对电场强度，纵向光学声子和杂质的依赖性。我们的研究结果对量子点量子比特的实验研究应该是有用的。