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Experimental Test of Relativistic Quantum State Collapse with Moving Reference Frames

Hugo Zbinden, Jurgen Brendel, Wolfgang Tittel, N. Gisin

Published Jan 1, 2000• 23 citations
OpenAlex

Abstract

An experimental test of relativistic wave-packet collapse is presented. Thetested model assumes that the collapse takes place in the reference framedetermined by the massive measuring detectors. Entangled photons are measuredat 10 km distance within a time interval of less than 5 ps. The two apparatusesare in relative motion so that both detectors, each in its own inertialreference frame, are first to perform the measurement. The data alwaysreproduces the quantum correlations and thus rule out a class of collapsemodels. This also sets a lower bound on the ''speed of quantum information'' to$10^{7}$ times the speed of light.

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Experimental test of relativistic quantum state collapse with moving reference frames

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An experimental test of relativistic wave-packet collapse is presented. The tested model assumes that the collapse takes place in the reference frame determined by the massive measuring detectors. Entangled photons are measured at 10 km distance within a time interval of less than 5 ps. The two apparatuses are in relative motion so that both detectors, each in its own inertial reference frame, are first to perform the measurement. The data always reproduces the quantum correlations and thus rule out a class of collapse models. The results also set a lower bound on the `speed of quantum information' to 2/3 ×10 7 and 3/2 ×10 4 times the speed of light in the Geneva and the background radiation reference frames, respectively. The very difficult and deep question of where the collapse takes place—if it takes place at all—is considered in a concrete experimental context.

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A thought experiment is presented that provides a hint as to how quantum wave functions can collapse in a relativistically consistent way. The thought experiment consists of a central source of photon pulses midway between two detectors, which is examined relativistically from both the lab frame and a frame moving with respect to the source and detectors. The total number of pulses between the two detectors is the only invariant and this leads to the idea that collapse might occur along special spacetime intervals, which we call symmetric spacetime intervals. In the current formalism of quantum mechanics, collapse is envisioned to occur “instantaneously”, in clear violation of relativity. It is shown that what the current formalism actually specifies is that collapse is merely spacelike. However, if quantum collapse occurs along symmetric spacetime intervals, then collapse of the wave function can be made consistent with relativity and all observers can agree upon which of two spacelike-separated causally connected events is the cause and which the effect. Nomenclature x = normalized distance in light seconds (ls) t = normalized time in seconds (s) γ = Lorentz factor s = spacetime interval u = normalized velocity (ls/s) c = speed of light (1.0 ls/s) y = a quantum object z = a quantum object d = separation between pulses (ls) L = separation between detectors (ls) ν = frequency (s-1) n = number of pulses β = slope of the symmetric interval (s/ls) I.

AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit (JPC)•Jul 9, 2006•7 citations
An experimental test of relativistic wave-packet collapse is presented. Thetested model assumes that the collapse takes place in the reference framedetermined by the massive measuring detectors. Entangled photons are measuredat 10 km distance within a time interval of less than 5 ps. The two apparatusesare in relative motion so that both detectors, each in its own inertialreference frame, are first to perform the measurement. The data alwaysreproduces the quantum correlations and thus rule out a class of collapsemodels. This also sets a lower bound on the ''speed of quantum information'' to10710^{7}107 times the speed of light.
An experimental test of relativistic wave-packet collapse is presented. The tested model assumes that the collapse takes place in the reference frame determined by the massive measuring detectors. Entangled photons are measured at 10 km distance within a time interval of less than 5 ps. The two apparatuses are in relative motion so that both detectors, each in its own inertial reference frame, are first to perform the measurement. The data always reproduces the quantum correlations and thus rule out a class of collapse models. The results also set a lower bound on the `speed of quantum information' to 2/3 ×10 7 and 3/2 ×10 4 times the speed of light in the Geneva and the background radiation reference frames, respectively. The very difficult and deep question of where the collapse takes place—if it takes place at all—is considered in a concrete experimental context.
We report on an experimental investigation of the tension between quantum nonlocality and relativity. Entangled photons are sent via an optical fiber network to two villages near Geneva, separated by more than 10 km where they are analyzed by interferometers. The photon pair source is set as precisely as possible in the center so that the two photons arrive at the detectors within a time interval of less than 5 ps (corresponding to a path length difference of less than 1 mm). One detector is set in motion so that both detectors, each in its own inertial reference frame, are first to do the measurement! The data always reproduces the quantum correlations, making it thus more difficult to consider the projection postulate as a compact description of real collapses of the wave function.
The instantaneous nature of quantum entanglement remains one of the most intriguing aspects of quantum mechanics. While the no-signaling theorem prohibits faster-than-light communication, the concept of a finite speed for the collapse of the quantum wavefunction has been a subject of philosophical debate. In this paper, we propose an experimental setup designed to test the speed of wavefunction collapse using entangled photon pairs over a distance of 10 km. By systematically varying the time delay between measurements and analyzing the resulting correlations, we aim to outline a method that could place bounds on the collapse speed without contradicting the no-signaling theorem. We argue that detecting a finite, possibly superluminal, speed of collapse could allow for maintaining realism and locality through high-speed remote synchronization, eliminating the need for hidden variables. We provide a detailed experimental design, including an algorithm and a Python implementation using the Cirq library to simulate the proposed experiment. Our goal is to motivate experimentalists to undertake this test, which could have profound implications for our understanding of quantum mechanics and the nature of reality.
The instantaneous nature of quantum entanglement remains one of the most intriguing aspects of quantum mechanics. While the no-signaling theorem prohibits faster-than-light communication, the concept of a finite speed for the collapse of the quantum wavefunction has been a subject of philosophical debate. In this paper, we propose an experimental setup designed to test the speed of wavefunction collapse using entangled photon pairs over a distance of 10 km. By systematically varying the time delay between measurements and analyzing the resulting correlations, we aim to outline a method that could place bounds on the collapse speed without contradicting the no-signaling theorem. We argue that detecting a finite, possibly superluminal, speed of collapse could allow for maintaining realism and locality through high-speed remote synchronization, eliminating the need for hidden variables. We provide a detailed experimental design, including an algorithm and a Python implementation using the Cirq library to simulate the proposed experiment. Our goal is to motivate experimentalists to undertake this test, which could have profound implications for our understanding of quantum mechanics and the nature of reality.
A still widely debated question in the field of relativistic quantum information is whether entanglement and the degree of violation of Bell's inequalities for massive relativistic particles are frame independent or not. At the core of this question is the effect that spin gets entangled with the momentum degree of freedom at relativistic velocities. Here, we show that Bell's inequalities for a pair of particles can be maximally violated in a special-relativistic regime, even without any postselection of the momentum of the particles. To this end, we use the methodology of quantum reference frames, which allows us to transform the problem to the rest frame of a particle, whose state can be in a superposition of relativistic momenta from the viewpoint of the laboratory frame. We show that, when the relative motion of two particles is noncollinear, the optimal measurements for violation of Bell's inequalities in the laboratory frame involve "coherent Wigner rotations." Moreover, the degree of violation of Bell's inequalities is independent of the choice of the quantum reference frame. Our results open up the possibility of extending entanglement-based quantum communication protocols to relativistic regimes.
A thought experiment is presented that provides a hint as to how quantum wave functions can collapse in a relativistically consistent way. The thought experiment consists of a central source of photon pulses midway between two detectors, which is examined relativistically from both the lab frame and a frame moving with respect to the source and detectors. The total number of pulses between the two detectors is the only invariant and this leads to the idea that collapse might occur along special spacetime intervals, which we call symmetric spacetime intervals. In the current formalism of quantum mechanics, collapse is envisioned to occur “instantaneously”, in clear violation of relativity. It is shown that what the current formalism actually specifies is that collapse is merely spacelike. However, if quantum collapse occurs along symmetric spacetime intervals, then collapse of the wave function can be made consistent with relativity and all observers can agree upon which of two spacelike-separated causally connected events is the cause and which the effect. Nomenclature x = normalized distance in light seconds (ls) t = normalized time in seconds (s) γ = Lorentz factor s = spacetime interval u = normalized velocity (ls/s) c = speed of light (1.0 ls/s) y = a quantum object z = a quantum object d = separation between pulses (ls) L = separation between detectors (ls) ν = frequency (s-1) n = number of pulses β = slope of the symmetric interval (s/ls) I.