TY - JOUR AU - Murray Holland AU - D. Walls AU - Peter Zoller BT - Physical Review Letters DA - 1991-09 DO - 10.1103/PhysRevLett.67.1716 PY - 1991 SP - 1716 EP - 1719 T2 - Physical Review Letters TI - Quantum nondemolition measurements of photon number by atomic beam deflection VL - 67 SN - 0031-9007 ER -