Ck†=(ck†c−k),Ck=(ckc−k†), 从而可以把哈密顿量改写成标准的Bogoliubov-de Gennes形式: H=12∑k∈BZCk†HkCk,Hk=(ϵkΔk∗~Δk~−ϵk) 其中ϵk=−tcosk−μ是动能项,Δk~=−iΔeiϕsink是傅立叶变换下的配对势。 于是,在Bogoliubov变换下,可以重写哈密顿...
像上面这个示意图,在PHS保护下的体系, 能量须要在零能级上下保持对称, μ=0 时kitaev chain的两端具有零能态,随着 μ 逐渐增大,两端的零能态在一定范围内保持,然而等 μ 增大到特定值,原本的零能级会向上下劈裂,在PHS下不可能出现只向一边移动的情况。 从前面周期性条件解析得到的能量值和数值计算的能谱图可...
Kitaev chain is an example of a new class of quantum critical phenomena—the topological phase transition. Mapping Pauli's spin operators of transverse field quantum Ising chain to spinless fermionic creation and annihilation operators by inverse Jordan-Wigner transformation leads to a Hamiltonian form...
We present a stochastic formulation of the Keldysh theory to calculate the conductance of a finite Kitaev chain coupled to two electron reservoirs. We study the dependence of the conductance on the number of sites in the chain and find that only for sufficiently long chains and in the regime ...
The fermionic Kitaev chain is a canonical model featuring topological Majorana zero modes1. We report the experimental realization of its bosonic analogue2 in a nano-optomechanical network, in which the parametric interactions induce beam-splitter coupling and two-mode squeezing among the nanomechanical ...
Majorana-zero-modes (MZMs) were predicted to exist as edge states of a physical system called the Kitaev chain. MZMs should host particles that are their own antiparticles and could be used as a basis for a qubit which is robust-to-noise. However, all attempts to prove their existence ...
We investigate the topological properties of a dimerized Kitaev chain with long-range couplings, including the intercell hopping and superconducting pairing terms. It is found that once the intercell hopping term appears, the size of the energy gap, the proportion of topological phases, and the to...
(zero energy) modes. In particular, we find that for some critical values of the transversal hoppingt1, and at a given transversal paring Δ1, the topological phase survives also when the Kitaev criterion for the single chain (Δ > 0, |μ| < 2t) is violated. Using a tight-binding ...
Outstandingly, the final result can be written as a simple analytical expression that underlines the link with the system's topological phases. 展开 关键词: Long-range correlationsMajorana/Kitaev chaintensor states DOI: 10.1088/2399-6528/aae4c5 年份: 2018 ...
三、Kitaev chain模型 我们上面用马约拉纳摸写出的哈密顿量可以利用下面的公式替换成费米子模: γ2n−1=(cn†+cn),γ2n=−i(cn†−cn) 我们发现,上面画出的两种配对方式是一维超导链的紧束缚模型(extreme limits of one tight-binding Hamiltonian for a one-dimensional superconducting wire): ...