Spin quantum well-like behavior in single-crystal Gd0.75La0.25FeO3

Quantum fluctuations in spin-ice-like Pr2Zr2O7.

Spin ice is a magnetic analog of H2O ice that harbors dense static disorder. Dipolar interactions between classical spins yield a frozen frustrated state with residual configurational Pauling entropy and emergent magnetic monopolar quasiparticles. Introducing quantum fluctuations is of great interest as this could melt spin ice and allow coherent propagation of monopoles. Here, we report experi...

Noise in single quantum well infrared photodetectors

The noise of the dark current and photocurrent is an important factor in operation of the quantum well infrared photodetectors ~QWIPs!. For typical operating conditions, the main source of fluctuations in QWIPs is generationrecombination noise associated with the excitation of carriers from the QWs into the continuum and their capture into the QWs. For applications the study of noise in QWIPs i...

Crystal orientation dependent intersubband transition in semipolar AlGaN/GaN single quantum well for optoelectronic applications

Quantum photonic devices in single-crystal diamond

Nitrogen–vacancy centers in diamond have outstanding quantum optical properties that enable applications in information processing and sensing. As with most solid-state systems for quantum photonic applications, the great promise lies in the capability to embed them in an on-chip optical network. Here we present basic integrated devices composed of diamond micro-ring resonators coupled to waveg...

WZW term in quantum mechanics: single spin

7.1 Quantum spin Let us consider a simple example of how Wess-Zumino effective Lagrangian appears from the “current algebra”. To simplify the story we take an example of quantum spin S. This is a quantum mechanical system with an SU(2) spin algebra playing the role of “current algebra” of quantum field theory. We have standard spin commutation relations [S, S] = i!S, (7.1) where a, b, c take va...