Tunneling Times and Studying the Effects of Dissipation

How much time does a tunneling particle spend in the barrier region?~ An answer to this question may be defined by considering a ``weak measurement'' in the sense of Aharonov, Albert, and Vaidman.~ A Larmor clock, which uses a spin degree of freedom to keep time, can implement such a measurement experimentally [1]. ~Here, we report the status of our experiment on measuring times for Bose-condensed Rubidium~atoms tunneling through a 1-micron optical barrier [2]. ~We also consider probing the quantum/classical transition by studying what happens when the Larmor measurement is made "strong" and/or under the influence of engineered dissipation [3]. [1] Steinberg, A. M. (1998). Time and history in quantum tunneling. \textit{Superlattices and Microstructures}, \textit{23}(3--4), 823--832. \underline {http://doi.org/10.1006/spmi.1997.0543} [2] Potnis, S., Ramos, R., Maeda, K., Carr, L. D., {\&} Steinberg, A. M. (2017). Interaction-Assisted Quantum Tunneling of a Bose-Einstein Condensate out of a Single Trapping Well. \textit{Physical Review Letters}, \textit{118}(6), 1--5. \underline {http://doi.org/10.1103/PhysRevLett.118.060402} [3] Steinberg, A. M. (1999). On energy transfer by detection of a tunneling atom. Korean Physical Society 35 (3), 122. (\underline {http://arxiv.org/abs/quant-ph/9904098})