JP3137478B2 - Electron wave interference device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is applied to a memory or a switching element as a quantum interference part of a quantum effect transistor. The present invention relates to an electron wave interference device that can obtain a quantum interference effect at room temperature and can prevent conduction from occurring even when a conductive ring is cut.

[0002]

2. Description of the Related Art Conventionally, this kind of electron wave interference device is shown in FIG.
As shown in FIG. 0, one side L is equal to
The two conductor lands 2a and 2b, each having a substantially square shape of 0 μm, and the width W _{1 of} the ring is several hundreds of degrees and the inner diameter D
Is formed by hetero-junction forming a conductive ring 3 of at least several μm and conductor paths 4a and 4b having a width W ₂ of several hundreds of degrees connecting the conductive ring 3 and the two conductor lands 2a and 2b. It had been.

[0003]

In such a conventional electron wave interference device, the width of the conductor paths 4a and 4b is several hundreds of degrees.
, The operating temperature becomes several degrees K due to phonon scattering and the like, and the quantum interference effect cannot be obtained at room temperature. There was a problem that conduction could not be achieved.

In order to obtain the quantum interference effect at room temperature, it is necessary to further narrow the conductor path. If the conductor path is made narrower, it becomes easy to cut, and a useful conductor path cannot be obtained. .

The present invention solves such a problem, and provides an electron wave interference device that can obtain a quantum interference effect at room temperature and can prevent conduction from being disabled even when a conductive ring is cut. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION The present invention provides a non-conductive substrate, two conductive lands formed on the substrate, and one conductive land formed between the two conductive lands on the substrate. An electro-magnetic interference device comprising a conductive ring and a thin conductive path connecting the conductive ring and the two conductive lands on the substrate, the conductive ring is formed by intersecting a large number of extremely thin straight lines. It is characterized by having a mesh shape.

[0007]

FIG. 11 schematically shows a pattern in a conventional example. In the conventional electron wave interference device, since the interference portion of the electrons is formed by the conductive ring 3, the electrons from the conductor land 2a branch at the point A, and the branched electrons merge at the point B. A phase difference occurs between these two rotations,
The conductance between points A and B periodically changes according to the phase difference. Here, by applying a magnetic field or an electric field to control the phase difference, a function as a transistor can be provided.

In the present invention, such a conductive ring 3 is formed in a mesh shape by a conductor path having a width of several tens of degrees, and is formed as an example as shown in FIG. In the case of such a mesh-like configuration, the portions inside the mesh of the conductive ring 13 are offset by the path integration, and the substantial path is only the outermost path. It becomes almost equivalent to the path of the ring 3. Also, even if one of the mesh-shaped portions is cut, any of the other portions is connected, so that even if the length of the path changes, there is no significant difference, and the cut makes it impossible to conduct. Can be avoided.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an embodiment of the present invention, and FIG. 2 is a diagram schematically showing a pattern in the embodiment of the present invention.

An embodiment of the present invention comprises a non-conductive substrate 1 and two conductive lands 2a and 2a formed on the substrate 1.
b and the two conductor lands 2a and 2b on the substrate 1.
And one conductive ring 13 formed between the conductive ring 3 and two conductive lands 2a and 2
b, and thin conductor tracks 14a and 14b connecting
Further, as a feature of the present invention, the conductive ring 13 is formed in a mesh shape formed by intersecting a large number of extremely thin straight lines. The widths W ₀ of the conductor paths 14a and 14b and the mesh-shaped conductor are several tens of degrees.

FIG. 3 is a sectional view showing an example of a laminated structure of the conductive ring portion in the embodiment of the present invention.

In this example, on a semi-insulating InP (indium phosphide) substrate 21, a barrier semiconductor layer 22 composed of AlAs (aluminum arsenide) of several hundred degrees
A mesh structure portion 23 composed of n, Ga, As (indium potassium arsenic) and AlAs (aluminum arsenide), a barrier semiconductor layer 24 composed of several hundreds of AlAs (aluminum arsenide), and this barrier semiconductor 24 The conductor portions 25 having the point contacts 25a penetrating and connected to the mesh structure portion 23 are sequentially laminated.

The barrier semiconductor layers 22 and 24 are MOCV
Metal organic chemical vapor deposition (D) method or MBE (molecular beam epitaxy:
Conductor portion 2 formed by a molecular epitaxial growth) method.
5 and the point contact 25a have a width of several tens.
Å, the length is several μm. This is formed by giving a semi-insulating InP substrate 21 an inclination angle of about 2 ° and using a technique using a scanning tunneling microscope (STM) to form a heterojunction. The element regions are separated by a mesa separation method.

FIG. 4 is a partially enlarged view of the mesh structure in the embodiment of the present invention, in which AlAs, In, Ga, and As are grown along the inclination angle, and the width and height thereof are about 15 ° (5 °). Atomic layer) is formed.

In the case of such a mesh structure, the portions in the mesh are canceled by the path integration as shown in FIG. 5, and the substantial path becomes effective only on the outside, as shown in FIG. As described above, it becomes substantially equivalent to the path of the conductive ring in the conventional example. In addition, even if any part of the path is cut due to the mesh structure, the other part is connected, so even if the length of the path changes, a large difference does not occur. With this configuration, it is possible to prevent the disconnection from occurring due to disconnection.

The conductive ring 1 thus constructed
When a phase difference is caused by a current, a magnetic field, an electric field, or the like in FIG. 3, the current flowing between the conductive rings 13 is changed by the phase difference as shown in FIG.

Here, the interference of electrons in the conductive ring 13 will be described using mathematical expressions.

When the vector potential is A,
The probability amplitude from C1 to C2 on the path shown in FIG. 8 can be defined as follows.

<C2 | C1> (1) Here, when a vector potential exists, A ≠ 0,
A case where there is not exists is represented by A = 0, and is represented as follows.

[0020]

(Equation 1) According to quantum mechanics, the relationship between (2-1) and (2-2) can be expressed as follows.

[0021]

(Equation 2) Equation (3) is a basic equation in which the probability [1] changes according to the phase [2] and electrons interfere.

[0022]

[Outside 1]

[0023]

[Outside 2] For example, considering an interference system as shown in FIG.

[0024]

(Equation 3) Here, using Green's theorem,

[0025]

(Equation 4)

[0026]

(Equation 5) And the probability [1] vibrates due to the magnetic field B.

[0027]

(Equation 6) Dividing this integral into n parts gives

[0028]

(Equation 7) Next

[0029]

(Equation 8) Sn (n = 1, 2,...): Area of each mesh Cn: path integral surrounding Sn is obtained, and it can be seen that only the outermost path is substantially effective.

[0030]

As described above, according to the present invention, the quantum interference effect can be obtained at room temperature, and the conductive ring is formed in a mesh even if a part of the conductive ring is cut. There is an effect that the connection state is maintained at such a place, so that no conduction failure occurs.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a pattern according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an example of a laminated structure of a conductive ring portion in the embodiment of the present invention.

FIG. 4 is a partially enlarged view of a mesh structure in the embodiment of the present invention.

FIG. 5 is a partially enlarged view of a mesh portion of the conductive ring according to the embodiment of the present invention.

FIG. 6 is a view showing a substantial path of a conductive ring in the embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between a phase difference and a current in the embodiment of the present invention.

FIG. 8 is a diagram showing an example of a route in a mesh according to the embodiment of the present invention.

FIG. 9 is a diagram illustrating an interference system according to an embodiment of the present invention.

FIG. 10 is a perspective view showing a configuration of a conventional example.

FIG. 11 is a diagram schematically showing a pattern in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2a, 2b Conductor land 3, 13 Conductive ring 4a, 4b, 14a, 14b Conductor path 21 Semi-insulating InP substrate 22, 24 Barrier semiconductor layer 23 Mesh structure part 25 Conductor part 25a Point contact

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/337 H01L 21/338 H01L 27/095 H01L 29/778 H01L 29/80-29/812 H01L 29 / 06

Claims (1)

(57) [Claims] A non-conductive substrate, two conductive lands formed on the substrate, one conductive ring formed on the substrate between the two conductive lands, In the electron wave interference device provided with the conductive ring and a thin conductor path connecting the two conductor lands, the conductive ring has a mesh shape formed by intersecting a large number of extremely thin straight lines. An electron wave interference device characterized by the above-mentioned.