Classical field approach to quantum weak measurements.

نویسندگان

  • Justin Dressel
  • Konstantin Y Bliokh
  • Franco Nori
چکیده

By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

4 Time problem in quantum mechanics and its analysis by the concept of weak measurements

Time problem in quantum mechanics and its analysis by the concept of weak measurements Abstract The model of weak measurements is applied to various problems, related to the time problem in quantum mechanics. The review and generalization of the theoretical analysis of the time problem in quantum mechanics based on the concept of weak measurements are presented. A question of the time interval ...

متن کامل

Interferometric weak value deflections: Quantum and classical treatments

Weak values [1] have presented or inspired intriguing possibilities for precision measurement. A recent example is by Hosten and Kwiat [2], where they were able to amplify the deflections arising from the spin Hall effect of light. The light fields used in their experiment, as well as in Ref. [3], were coherent quasiclassical fields and no apparent quantum mechanical system was employed in eith...

متن کامل

On Quantum Tunneling in Real Time

A detailed real time description of quantum tunneling in the semiclassical limit is given, using complex classical trajectories. This picture connects naturally with the ideas of post-selection and weak measurement introduced by Aharonov and collaborators. I show that one can precisely identify the complex classical trajectory which a post-selected tunneling particle has followed, and which dom...

متن کامل

Weak Force Measurement in Bistable Optomechanical System

One of the main milestones in the study of opto-mechanical system is to increase the sensitivity of weak forces measurement up to the standard quantum limit. We have studied the detection of weak force under a bistable condition in red detuned regime. In this case, dynamics of the system behaves asymptotically similar to stationary state and applying external force affects phase and fluctuation...

متن کامل

Noninvasiveness and time symmetry of weak measurements

Measurements in classical and quantum physics are described in fundamentally different ways. Nevertheless, one can formally define similar measurement procedures with respect to the disturbance they cause. Obviously, strong measurements, both classical and quantum, are invasive—they disturb the measured system. We show that it is possible to define general weak measurements, which are noninvasi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Physical review letters

دوره 112 11  شماره 

صفحات  -

تاریخ انتشار 2014