In this paper, we study the topological properties of non-Hermitian Su-Schrieffer-Heeger (SSH) lattices by periodically introducing onsite imaginary potentials in the manner of ($i{\gamma }_1$, $-i{\gamma }_2$, $-i{\gamma }_1$, $i{\gamma }_2$), where ${\gamma }_1$ and ${\gamma }_2$ are the imaginary-potential strengths. Results show that by changing the lattice to a tetratomic non-Hermitian system, such imaginary potentials induce the nontrivial transition of the topological properties of the SSH system. First, the topologically nontrivial region is extended, followed by the non-Hermitian spontaneous breaking of the anti-$\mathcal{P}T$ symmetry. In addition, a new edge state appears, but its locality is different from the state induced by the Hermitian SSH lattice. If such potentials are strong enough, the bulk states of this system can become purely imaginary states. We believe that these imaginary potentials play special roles in modulating the topological properties of the non-Hermitian SSH lattice.

Recently, altermagnetism (AM) in condensed matter systems has attracted much attention due to the physical properties arising from alternating spins in both real space and reciprocal space. In our work, we propose a stable monolayer Janus Nb2SeTeO with altermagnetic ground state and spin-valley locking (SVL) effect. The monolayer Janus Nb2SeTeO exhibits a multipiezo effect with a large out-of-plane piezoelectricity and piezovalley effect with large valley polarization. The piezovalley effect is induced by uniaxial strain effect in different directions, which contributes the anomalous valley Hall effect (AVHE) observed in AM systems. Moreover, compressive uniaxial strain could induce quantum anomalous Hall effect (QAHE) in the AM system, where the dissipationless topological edge states' chirality could be manipulated by the direction of uniaxial strain. These manifest topological phase transitions could be realized via piezovalley effect in the AM system. Furthermore, the AM quantum spin Hall effect (QSHE) could be induced by biaxial strain effect, which contributes quantized spin Hall conductance. Our work reveals that strain-engineering technique could serve as an important method to tune dissipationless edge states in monolayer Janus Nb2SeTeO. By designing the SVL effect, topological physics could be emerged in AM systems such as AVHE, QAHE, and QSHE.

Enhanced oxygen reduction reaction over a high-entropy cobalt-free perovskite with a nominal formula of La _1/6 Pr _1/6 Nd _1/6 Ba _1/6 Sr _1/6 Ca _1/6 FeO _{3− δ} .

By considering Majorana zero modes to laterally couple to the quantum dot, we evaluate the thermoelectric effect in one single-dot system. The calculation results show that if one Majorana zero mode couples to the dot, the thermoelectric effect will change but its efficiency cannot be improved. However, notable thermoelectric effect takes place when two Majorana zero modes are introduced simultaneously. We believe that the findings in this work provide an alternative method for the detection of the zero mode of Majorana bound state.

In this paper, we study the effect of $\mathcal{PT}$-symmetric complex potentials on the transport properties of one non-Hermitian system, which is formed by the coupling between a triple-quantum-dot molecule and two semi-infinite leads. As a result, it is found that the $\mathcal{PT}$-symmetric imaginary potentials have pronounced effects on the transport properties of such a system, including changes from antiresonance to resonance, shift of antiresonance, and occurrence of new antiresonance, which are determined by the interdot and dot-lead coupling manners. This paper can be helpful in understanding the quantum transport behaviors modified by the $\mathcal{P}T$ symmetry in non-Hermitian discrete systems.