2012/12/31 by Shengjun Wu · 97 citations
Computer Science · Physics and Astronomy · #Algorithm #Artificial intelligence #Biology #Computer science #Density matrix #Element (criminal law) #Function (biology) #Materials science #Matrix (chemical analysis) #Matrix element #Optics #Particle physics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Quantum state #Quantum tomography #Selection (genetic algorithm) #State (computer science) #Statistical physics #Tomography #Weak measurement #Work (physics) #quant-ph
paper · pdf · doi:10.1038/srep01193
published in Scientific Reports 3(1), 1193 (Nature Portfolio) · 7 pages, 2 figure
arxiv created 2013/02/01 · openalex publication_date 2013/02/01 · arxiv updated 2013/02/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recent work has revealed that the wave function of a pure state can be measured directly and that complementary knowledge of a quantum system can be obtained simultaneously by weak measurements. However, the original scheme applies only to pure states, and it is not efficient because most of the data are discarded by post-selection. Here, we propose tomography schemes for pure states and for mixed states via weak measurements, and our schemes are more efficient because we do not discard any data. Furthermore, we demonstrate that any matrix element of a general state can be directly read from an appropriate weak measurement. The density matrix (with all of its elements) represents all that is directly accessible from a general measurement.