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BGU. Two-path Interference with a Single Quantum Slit or Mirror. Daniel Rohrlich, Yakov Neiman , Yonathan Japha, and Ron Folman Department of Physics and Ilze Katz Center for Meso- and Nanoscale Science, BGU, Israel. Two path interference. 2.
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BGU Two-path Interference with a Single Quantum Slit or Mirror Daniel Rohrlich, Yakov Neiman, Yonathan Japha, and Ron Folman Department of Physics and Ilze Katz Center for Meso- and Nanoscale Science, BGU, Israel
Single particle superposition A single particle in a superposition of two locations is prepared in a double well potential and then the potential is turned off. The wavepackets expand and overlap after t=pMdw/h Initial state of probe+ Target: 3
Condition for interference: loss of orthogonality of target states After scattering: Final state: It final target states (left and right) remain orthogonal then there Is no interference! Final state is an entangled state. The phase a have no effect. 4
1D example: One-mirror Fabry-Perot In the special case M=m: pfin=Pin Transfer of orthogonality from target to probe 5
Suppression of visibility If the initial probe momentum has a spread pin 2 The probe induces an effective coherence length on the target. 7
Transfer of orthogonality Condition for full interference 9
Summary and conclusions • Two-path interference by scattering off a single free quantum particle in a superposition of two locations is possible. • Interference is suppressed by initial momentum spread of the probe particle or by measurement precision. • Double slit interference from a single slit is possible when the mass of the target is comparable to the mass of the probe (or smaller). • The condition for interference is loss of orthogonality of the target states or equivalently purity of the probe state. 13