Experimental evidence for non-exponential decay in quantum tunnelling

被引：280

作者：

Wilkinson, SR ^{[1
]}

Bharucha, CF ^{[1
]}

Fischer, MC ^{[1
]}

Madison, KW ^{[1
]}

Morrow, PR ^{[1
]}

Niu, Q ^{[1
]}

Sundaram, B ^{[1
]}

Raizen, MG ^{[1
]}

机构：

[1] UNIV TEXAS, DEPT PHYS, AUSTIN, TX 78712 USA

来源：

NATURE | 1997年 / 387卷 / 6633期

关键词：

D O I：

10.1038/42418

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

An exponential decay law is the universal hallmark of unstable systems and is observed in all fields of science. This law is not, however, fully consistent with quantum mechanics and deviations from exponential decay have been predicted for short as well as long times(1-8), Such deviations have not hitherto been observed experimentally. Here we present experimental evidence for short-time deviation from exponential decay in a quantum tunnelling experiment, Our system consists of ultra-cold sodium atoms that are trapped in an accelerating periodic optical potential created by a standing wave of light. Atoms can escape the wells by quantum tunnelling, and the number that remain can be measured as a function of interaction time for a fixed value of the well depth and acceleration. We observe that for short times the survival probability is initially constant before developing the characteristics of exponential decay. The conceptual simplicity of the experiment enables a detailed comparison with theoretical predictions.

引用

页码：575 / 577

页数：3

共 15 条

[1]

BALLENTINE LE, 1990, QUANTUM MECH

[2] Bloch oscillations of atoms in an optical potential [J].