p波相互作用するフェルミ原子気体の衝突特性

電気通信大学201

p波相互作用するフェルミ原子気体の衝突特性

電気通信大学201

Multiqubit quantum phase gate using four-level superconducting quantum interference devices coupled to superconducting resonator

In this paper, we propose a scheme to realize three-qubit quantum phase gate of one qubit simultaneously controlling two target qubits using four-level superconducting quantum interference devices (SQUIDs) coupled to a superconducting resonator. The two lowest levels |0> and |1> of each SQUID are used to represent logical states while the higher energy levels |2> and |3> are utilized for gate realization. Our scheme does not require adiabatic passage, second order detuning, and the adjustment of the level spacing during gate operation which reduce the gate time significantly. The scheme is generalized for an arbitrary n-qubit quantum phase gate. We also apply the scheme to implement three-qubit quantum Fourier transform. key words: quantum phase gate, superconducting quantum interference devices (SQUIDs), superconducting resonator, quantum Fourier transformComment: 14 pages, 7 figure

Scaling Law for Three-body Collisions in Identical Fermions with pp-wave Interactions

We experimentally confirmed the threshold behavior and scattering length scaling law of the three-body loss coefficients in an ultracold spin-polarized gas of $^6$Li atoms near a $p$-wave Feshbach resonance. We measured the three-body loss coefficients as functions of temperature and scattering volume, and found that the threshold law and the scattering length scaling law hold in limited temperature and magnetic field regions. We also found that the breakdown of the scaling laws is due to the emergence of the effective-range term. This work is an important first step toward full understanding of the loss of identical fermions with $p$-wave interactions.Comment: 5 pages, 4 figure