Detecting Macroscopic Indefiniteness of Cat States in Bosonic Interferometers

The paradigm of Schrodinger’s cat illustrates how specific superposition states preclude the assignment of definite properties to a macroscopic object (realism). In this work we develop a method to investigate the indefiniteness of cat states using currently available cold atom technology. The method we propose, uses observation of a statistical distribution to demonstrate the macroscopic distinction between dead and alive states and the interferometric sensitivity(Fisher Information) to detect the indefiniteness of the vital status of the cat. We show how these two observations can provide information about the quantum state without full quantum state tomagraphy. We test this method using a cat state proposed by Gordon et. al.(PRA 59 4623), which is dynamically produced from a coherent state. As a control, we consider a set of states produced using the same dynamical procedure acting on an initial thermal distribution. Numerically simulating our proposed method, we show that as the temperature of this initial state is increased, the produced state undergoes a quantum to classical crossover where the indefiniteness of the vital status of the is lost, while the macroscopic distinction between dead and alive states of the cat is maintained.