Influence of environment and geometry on measured quantum coherence in InGaAs mesoscopic wires and stadia

[摘要] Lithographically fabricated mesoscopic wires and stadia, coupled to a decohering classical environment by two side-wires, were studied using low-temperature quantum transport to obtain quantum phase coherence lengths. Longer phase coherence lengths were observed in longer wires, an effect due to environmental coupling decoherence being mitigated by averaging over longer wire lengths. In stadia the dominant decoherence mechanism appears as device-device, here stadium-wire, coupling decoherence rather than environmental coupling decoherence. Consistency between the experimental results and a decoherence mechanism due to stadium-wire coupling is found in the relation between lower decoherence rate and relative geometrical similarity between the stadia and their connecting wires.

[发布机构] Virginia Tech, Department of Physics, Blacksburg; VA; 24061, United States^1;Ecole Polytechnique, Department of Physics, Palaiseau; 91128, France^2

[关键词] Connecting wires;Decoherence rates;Influence of environments;Low temperatures;Mesoscopic wires;Phase-coherence length;Quantum coherence;Quantum transport